diff --git a/conan/tools/cmake/toolchain.py b/conan/tools/cmake/toolchain.py
index 39994397e37..faed8f5d4a5 100644
--- a/conan/tools/cmake/toolchain.py
+++ b/conan/tools/cmake/toolchain.py
@@ -245,7 +245,7 @@ class ParallelBlock(Block):
 
     def context(self):
         # TODO: Check this conf
-        max_cpu_count = self._conanfile.conf["tools.cmake.cmaketoolchain"].msvc_parallel_compile
+        max_cpu_count = self._conanfile.conf["tools.cmake.cmaketoolchain:msvc_parallel_compile"]
 
         if max_cpu_count:
             return {"parallel": max_cpu_count}
@@ -278,7 +278,7 @@ def context(self):
         libcxx_str = str(self._conanfile.settings.compiler.libcxx)
 
         # TODO: Do not use envvar! This has to be provided by the user somehow
-        android_ndk = self._conanfile.conf["tools.android"].ndk_path
+        android_ndk = self._conanfile.conf["tools.android:ndk_path"]
         if not android_ndk:
             raise ConanException('CMakeToolchain needs tools.android:ndk_path configuration defined')
         android_ndk = android_ndk.replace("\\", "/")
@@ -376,7 +376,7 @@ def context(self):
         cmake_prefix_path = "${CMAKE_CURRENT_LIST_DIR}"
         cmake_module_path = "${CMAKE_CURRENT_LIST_DIR}"
         find_package_prefer_config = "ON"  # assume ON by default if not specified in conf
-        prefer_config = self._conanfile.conf["tools.cmake.cmaketoolchain"].find_package_prefer_config
+        prefer_config = self._conanfile.conf["tools.cmake.cmaketoolchain:find_package_prefer_config"]
         if prefer_config is not None and prefer_config.lower() in ("false", "0", "off"):
             find_package_prefer_config = "OFF"
 
diff --git a/conan/tools/files/files.py b/conan/tools/files/files.py
index 86a3855aefb..b1c505e027e 100644
--- a/conan/tools/files/files.py
+++ b/conan/tools/files/files.py
@@ -123,9 +123,9 @@ def download(conanfile, url, filename, verify=True, out=None, retry=None, retry_
     config = conanfile.conf
 
     # It might be possible that users provide their own requester
-    retry = retry if retry is not None else int(config["tools.files.download"].retry)
+    retry = retry if retry is not None else int(config["tools.files.download:retry"])
     retry = retry if retry is not None else 1
-    retry_wait = retry_wait if retry_wait is not None else int(config["tools.files.download"].retry_wait)
+    retry_wait = retry_wait if retry_wait is not None else int(config["tools.files.download:retry_wait"])
     retry_wait = retry_wait if retry_wait is not None else 5
 
     checksum = sha256 or sha1 or md5
diff --git a/conan/tools/gnu/autotools.py b/conan/tools/gnu/autotools.py
index fd0329e3d1e..93300936075 100644
--- a/conan/tools/gnu/autotools.py
+++ b/conan/tools/gnu/autotools.py
@@ -63,7 +63,7 @@ def make(self):
                                                        cpu_count_option]),
                                 win_bash=self._win_bash, subsystem=self.subsystem)"""
 
-        make_program = self._conanfile.conf["tools.gnu"].make_program
+        make_program = self._conanfile.conf["tools.gnu:make_program"]
         if make_program is None:
             make_program = "mingw32-make" if use_win_mingw(self._conanfile) else "make"
         # Need to activate the buildenv if existing
diff --git a/conan/tools/gnu/make.py b/conan/tools/gnu/make.py
index fa48776cab3..8f7fc3729f4 100644
--- a/conan/tools/gnu/make.py
+++ b/conan/tools/gnu/make.py
@@ -1,5 +1,5 @@
 def make_jobs_cmd_line_arg(conanfile):
-    njobs = conanfile.conf["tools.gnu.make"].jobs or \
-            conanfile.conf["tools.build"].processes
+    njobs = conanfile.conf["tools.gnu.make:jobs"] or \
+            conanfile.conf["tools.build:processes"]
     if njobs:
         return "-j{}".format(njobs)
diff --git a/conan/tools/meson/meson.py b/conan/tools/meson/meson.py
index a137e22c9c2..bd982d3d785 100644
--- a/conan/tools/meson/meson.py
+++ b/conan/tools/meson/meson.py
@@ -5,8 +5,8 @@
 
 
 def ninja_jobs_cmd_line_arg(conanfile):
-    njobs = conanfile.conf["tools.ninja"].jobs or \
-            conanfile.conf["tools.build"].processes
+    njobs = conanfile.conf["tools.ninja:jobs"] or \
+            conanfile.conf["tools.build:processes"]
     if njobs:
         return "-j{}".format(njobs)
 
diff --git a/conan/tools/microsoft/msbuild.py b/conan/tools/microsoft/msbuild.py
index 6c799b02880..9ff60ab0985 100644
--- a/conan/tools/microsoft/msbuild.py
+++ b/conan/tools/microsoft/msbuild.py
@@ -4,7 +4,7 @@
 
 
 def msbuild_verbosity_cmd_line_arg(conanfile):
-    verbosity = conanfile.conf["tools.microsoft.msbuild"].verbosity
+    verbosity = conanfile.conf["tools.microsoft.msbuild:verbosity"]
     if verbosity:
         if verbosity not in ("Quiet", "Minimal", "Normal", "Detailed", "Diagnostic"):
             raise ConanException("Unknown msbuild verbosity: {}".format(verbosity))
@@ -12,8 +12,8 @@ def msbuild_verbosity_cmd_line_arg(conanfile):
 
 
 def msbuild_max_cpu_count_cmd_line_arg(conanfile):
-    max_cpu_count = conanfile.conf["tools.microsoft.msbuild"].max_cpu_count or \
-                    conanfile.conf["tools.build"].processes
+    max_cpu_count = conanfile.conf["tools.microsoft.msbuild:max_cpu_count"] or \
+                    conanfile.conf["tools.build:processes"]
     if max_cpu_count:
         return "/m:{}".format(max_cpu_count)
 
diff --git a/conan/tools/microsoft/msbuilddeps.py b/conan/tools/microsoft/msbuilddeps.py
index c8f7cffc1d8..a5714598fd1 100644
--- a/conan/tools/microsoft/msbuilddeps.py
+++ b/conan/tools/microsoft/msbuilddeps.py
@@ -103,7 +103,7 @@ def __init__(self, conanfile):
         self.output_path = os.getcwd()
         # ca_exclude section
         self.exclude_code_analysis = None
-        ca_exclude = self._conanfile.conf["tools.microsoft.msbuilddeps"].exclude_code_analysis
+        ca_exclude = self._conanfile.conf["tools.microsoft.msbuilddeps:exclude_code_analysis"]
         if ca_exclude is not None:
             # TODO: Accept single strings, not lists
             self.exclude_code_analysis = eval(ca_exclude)
diff --git a/conan/tools/microsoft/toolchain.py b/conan/tools/microsoft/toolchain.py
index da792ea6ab0..b3ea986422b 100644
--- a/conan/tools/microsoft/toolchain.py
+++ b/conan/tools/microsoft/toolchain.py
@@ -41,7 +41,7 @@ def vs_ide_version(conanfile):
     compiler_version = (conanfile.settings.get_safe("compiler.base.version") or
                         conanfile.settings.get_safe("compiler.version"))
     if compiler == "msvc":
-        toolset_override = conanfile.conf["tools.microsoft.msbuild"].vs_version
+        toolset_override = conanfile.conf["tools.microsoft.msbuild:vs_version"]
         if toolset_override:
             visual_version = toolset_override
         else:
@@ -160,7 +160,7 @@ def format_macro(key, value):
         cppstd = "stdcpp%s" % self.cppstd if self.cppstd else ""
         runtime_library = self.runtime_library
         toolset = self.toolset
-        compile_options = self._conanfile.conf["tools.microsoft.msbuildtoolchain"].compile_options
+        compile_options = self._conanfile.conf["tools.microsoft.msbuildtoolchain:compile_options"]
         if compile_options is not None:
             compile_options = eval(compile_options)
             self.compile_options.update(compile_options)
diff --git a/conans/client/conf/required_version.py b/conans/client/conf/required_version.py
index 24d46ddb3e4..f06342d663c 100644
--- a/conans/client/conf/required_version.py
+++ b/conans/client/conf/required_version.py
@@ -30,7 +30,7 @@ def check_required_conan_version(cache_folder, out):
     if required_range:
         validate_conan_version(required_range)
 
-    required_range_new = cache.new_config["core"].required_conan_version
+    required_range_new = cache.new_config["core:required_conan_version"]
     if required_range_new:
         if six.PY2 and not isinstance(required_range_new, str):
             required_range_new = required_range_new.encode()
diff --git a/conans/client/generators/__init__.py b/conans/client/generators/__init__.py
index 7c941caf361..03ea1213a47 100644
--- a/conans/client/generators/__init__.py
+++ b/conans/client/generators/__init__.py
@@ -207,7 +207,7 @@ def write_toolchain(conanfile, path, output):
                 conanfile.generate()
 
     # tools.env.virtualenv:auto_use will be always True in Conan 2.0
-    if conanfile.conf["tools.env.virtualenv"].auto_use and conanfile.virtualenv:
+    if conanfile.conf["tools.env.virtualenv:auto_use"] and conanfile.virtualenv:
         with chdir(path):
             from conan.tools.env.virtualenv import VirtualEnv
             env = VirtualEnv(conanfile)
diff --git a/conans/client/graph/graph_binaries.py b/conans/client/graph/graph_binaries.py
index e2bcb8602ba..f9cb92abe2a 100644
--- a/conans/client/graph/graph_binaries.py
+++ b/conans/client/graph/graph_binaries.py
@@ -340,7 +340,7 @@ def _compute_package_id(self, node, default_package_id_mode, default_python_requ
                                           default_python_requires_id_mode=
                                           default_python_requires_id_mode)
 
-        if not self._cache.new_config["core.package_id"].msvc_visual_incompatible:
+        if not self._cache.new_config["core.package_id:msvc_visual_incompatible"]:
             msvc_compatible = conanfile.info.msvc_compatible()
             if msvc_compatible:
                 conanfile.compatible_packages.append(msvc_compatible)
diff --git a/conans/model/conf.py b/conans/model/conf.py
index 41fa6b8ed4d..bae38aba373 100644
--- a/conans/model/conf.py
+++ b/conans/model/conf.py
@@ -4,8 +4,8 @@
 
 
 DEFAULT_CONFIGURATION = {
-    "core.required_conan_version": "Will raise if the current Conan version does not match the defined version range.",
-    "core.package_id.msvc_visual_incompatible": "Allows opting-out the fallback from the new msvc compiler to the Visual Studio compiler existing binaries",
+    "core:required_conan_version": "Will raise if the current Conan version does not match the defined version range.",
+    "core.package_id:msvc_visual_incompatible": "Allows opting-out the fallback from the new msvc compiler to the Visual Studio compiler existing binaries",
     "tools.microsoft.msbuild:verbosity": "Verbosity level for MSBuild: 'Quiet', 'Minimal', 'Normal', 'Detailed', 'Diagnostic'",
     "tools.microsoft.msbuild:max_cpu_count": "Argument for the /m (/maxCpuCount) when running MSBuild",
     "tools.microsoft.msbuild:vs_version": "Defines the compiler version when using using the new msvc compiler",
@@ -24,35 +24,6 @@
 }
 
 
-class _ConfModule(object):
-    """
-    a dictionary of key: values for each config property of a module
-    like "tools.cmake.CMake"
-    """
-    def __init__(self):
-        self._confs = {}  # Component => dict {config-name: value}
-
-    def __getattr__(self, item):
-        return self._confs.get(item)
-
-    def update(self, other):
-        """
-        :type other: _ConfModule
-        """
-        self._confs.update(other._confs)
-
-    def set_value(self, k, v):
-        if k != k.lower():
-            raise ConanException("Conf key '{}' must be lowercase".format(k))
-        self._confs[k] = v
-
-    def __repr__(self):
-        return "_ConfModule: " + repr(self._confs)
-
-    def items(self):
-        return self._confs.items()
-
-
 def _is_profile_module(module_name):
     # These are the modules that are propagated to profiles and user recipes
     _user_modules = "tools.", "user."
@@ -62,46 +33,40 @@ def _is_profile_module(module_name):
 class Conf(object):
 
     def __init__(self):
-        self._conf_modules = {}  # module_name => _ConfModule
+        self._values = {}  # property: value
 
-    def __getitem__(self, module_name):
-        return self._conf_modules.get(module_name, _ConfModule())
+    def __getitem__(self, name):
+        return self._values.get(name)
+
+    def __setitem__(self, name, value):
+        if name != name.lower():
+            raise ConanException("Conf '{}' must be lowercase".format(name))
+        self._values[name] = value
 
     def __repr__(self):
-        return "Conf: " + repr(self._conf_modules)
+        return "Conf: " + repr(self._values)
 
     def items(self):
-        return self._conf_modules.items()
+        return self._values.items()
 
     def filter_user_modules(self):
         result = Conf()
-        for k, v in self._conf_modules.items():
+        for k, v in self._values.items():
             if _is_profile_module(k):
-                result._conf_modules[k] = v
+                result._values[k] = v
         return result
 
     def update(self, other):
         """
         :type other: Conf
         """
-        for module_name, module_conf in other._conf_modules.items():
-            existing = self._conf_modules.get(module_name)
-            if existing:
-                existing.update(module_conf)
-            else:
-                self._conf_modules[module_name] = module_conf
-
-    def set_value(self, module_name, k, v):
-        if module_name != module_name.lower():
-            raise ConanException("Conf module '{}' must be lowercase".format(module_name))
-        self._conf_modules.setdefault(module_name, _ConfModule()).set_value(k, v)
+        self._values.update(other._values)
 
     @property
     def sha(self):
         result = []
-        for name, values in sorted(self.items()):
-            for k, v in sorted(values.items()):
-                result.append("{}:{}={}".format(name, k, v))
+        for k, v in sorted(self._values.items()):
+            result.append("{}={}".format(k, v))
         return "\n".join(result)
 
 
@@ -158,12 +123,11 @@ def dumps(self):
         # It is necessary to convert the None for sorting
         for pattern, conf in sorted(self._pattern_confs.items(),
                                     key=lambda x: ("", x[1]) if x[0] is None else x):
-            for name, values in sorted(conf.items()):
-                for k, v in sorted(values.items()):
-                    if pattern:
-                        result.append("{}:{}:{}={}".format(pattern, name, k, v))
-                    else:
-                        result.append("{}:{}={}".format(name, k, v))
+            for name, value in sorted(conf.items()):
+                if pattern:
+                    result.append("{}:{}={}".format(pattern, name, value))
+                else:
+                    result.append("{}={}".format(name, value))
         return "\n".join(result)
 
     def loads(self, text, profile=False):
@@ -174,20 +138,19 @@ def loads(self, text, profile=False):
                 continue
             try:
                 left, value = line.split("=", 1)
+                value = value.strip()
+                left = left.strip()
+                if left.count(":") >= 2:
+                    pattern, name = left.split(":", 1)
+                else:
+                    pattern, name = None, left
             except Exception:
                 raise ConanException("Error while parsing conf value '{}'".format(line))
-            value = value.strip()
-            tokens = left.strip().split(":", 2)
-            if len(tokens) == 3:
-                pattern, conf_module, name = tokens
-            else:
-                assert len(tokens) == 2
-                conf_module, name = tokens
-                pattern = None
-            if not _is_profile_module(conf_module):
+
+            if not _is_profile_module(name):
                 if profile:
                     raise ConanException("[conf] '{}' not allowed in profiles".format(line))
                 if pattern is not None:
                     raise ConanException("Conf '{}' cannot have a package pattern".format(line))
             conf = self._pattern_confs.setdefault(pattern, Conf())
-            conf.set_value(conf_module, name, value)
+            conf[name] = value
diff --git a/conans/test/integration/configuration/conf/test_conf.py b/conans/test/integration/configuration/conf/test_conf.py
index 300c0b0fcb1..dc943a14a4a 100644
--- a/conans/test/integration/configuration/conf/test_conf.py
+++ b/conans/test/integration/configuration/conf/test_conf.py
@@ -16,9 +16,8 @@ def client():
 
         class Pkg(ConanFile):
             def generate(self):
-                for k, conf in self.conf.items():
-                    for name, value in conf.items():
-                        self.output.info("{}${}${}".format(k, name, value))
+                for k, v in self.conf.items():
+                    self.output.info("{}${}".format(k, v))
         """)
     client.save({"conanfile.py": conanfile})
     return client
@@ -40,23 +39,23 @@ def test_basic_composition(client):
     client.save({"profile1": profile1,
                  "profile2": profile2})
     client.run("install . -pr=profile1")
-    assert "tools.microsoft.msbuild$verbosity$Quiet" in client.out
-    assert "tools.microsoft.msbuild$performance$Slow" in client.out
-    assert "tools.cmake.cmake$verbosity$Extra" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Quiet" in client.out
+    assert "tools.microsoft.msbuild:performance$Slow" in client.out
+    assert "tools.cmake.cmake:verbosity$Extra" in client.out
 
     client.run("install . -pr=profile1 -pr=profile2")
-    assert "tools.microsoft.msbuild$verbosity$Minimal" in client.out
-    assert "tools.microsoft.msbuild$performance$Slow" in client.out
-    assert "tools.microsoft.msbuild$robustness$High" in client.out
-    assert "tools.cmake.cmake$verbosity$Extra" in client.out
-    assert "tools.meson.meson$verbosity$Super" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Minimal" in client.out
+    assert "tools.microsoft.msbuild:performance$Slow" in client.out
+    assert "tools.microsoft.msbuild:robustness$High" in client.out
+    assert "tools.cmake.cmake:verbosity$Extra" in client.out
+    assert "tools.meson.meson:verbosity$Super" in client.out
 
     client.run("install . -pr=profile2 -pr=profile1")
-    assert "tools.microsoft.msbuild$verbosity$Quiet" in client.out
-    assert "tools.microsoft.msbuild$performance$Slow" in client.out
-    assert "tools.microsoft.msbuild$robustness$High" in client.out
-    assert "tools.cmake.cmake$verbosity$Extra" in client.out
-    assert "tools.meson.meson$verbosity$Super" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Quiet" in client.out
+    assert "tools.microsoft.msbuild:performance$Slow" in client.out
+    assert "tools.microsoft.msbuild:robustness$High" in client.out
+    assert "tools.cmake.cmake:verbosity$Extra" in client.out
+    assert "tools.meson.meson:verbosity$Super" in client.out
 
 
 def test_basic_inclusion(client):
@@ -77,11 +76,11 @@ def test_basic_inclusion(client):
                  "profile2": profile2})
 
     client.run("install . -pr=profile2")
-    assert "tools.microsoft.msbuild$verbosity$Minimal" in client.out
-    assert "tools.microsoft.msbuild$performance$Slow" in client.out
-    assert "tools.microsoft.msbuild$robustness$High" in client.out
-    assert "tools.cmake.cmake$verbosity$Extra" in client.out
-    assert "tools.meson.meson$verbosity$Super" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Minimal" in client.out
+    assert "tools.microsoft.msbuild:performance$Slow" in client.out
+    assert "tools.microsoft.msbuild:robustness$High" in client.out
+    assert "tools.cmake.cmake:verbosity$Extra" in client.out
+    assert "tools.meson.meson:verbosity$Super" in client.out
 
 
 def test_composition_conan_conf(client):
@@ -99,11 +98,11 @@ def test_composition_conan_conf(client):
         """)
     client.save({"profile": profile})
     client.run("install . -pr=profile")
-    assert "tools.microsoft.msbuild$verbosity$Minimal" in client.out
-    assert "tools.microsoft.msbuild$performance$Slow" in client.out
-    assert "tools.microsoft.msbuild$robustness$High" in client.out
-    assert "tools.cmake.cmake$verbosity$Extra" in client.out
-    assert "tools.meson.meson$verbosity$Super" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Minimal" in client.out
+    assert "tools.microsoft.msbuild:performance$Slow" in client.out
+    assert "tools.microsoft.msbuild:robustness$High" in client.out
+    assert "tools.cmake.cmake:verbosity$Extra" in client.out
+    assert "tools.meson.meson:verbosity$Super" in client.out
 
 
 def test_new_config_file(client):
@@ -116,9 +115,9 @@ def test_new_config_file(client):
         """)
     save(client.cache.new_config_path, conf)
     client.run("install .")
-    assert "tools.microsoft.msbuild$verbosity$Minimal" in client.out
-    assert "user.mycompany.myhelper$myconfig$myvalue" in client.out
-    assert "tools.cmake.cmake$generator$X" in client.out
+    assert "tools.microsoft.msbuild:verbosity$Minimal" in client.out
+    assert "user.mycompany.myhelper:myconfig$myvalue" in client.out
+    assert "tools.cmake.cmake:generator$X" in client.out
     assert "no_locks" not in client.out
     assert "read_only" not in client.out
 
diff --git a/conans/test/unittests/model/test_conf.py b/conans/test/unittests/model/test_conf.py
index 285362a71a7..f66ac378aa9 100644
--- a/conans/test/unittests/model/test_conf.py
+++ b/conans/test/unittests/model/test_conf.py
@@ -21,10 +21,10 @@ def test_conf_definition(conf_definition):
     # Round trip
     assert c.dumps() == text
     # access
-    assert c["tools.microsoft.msbuild"].verbosity == "minimal"
-    assert c["user.company.toolchain"].flags == "someflags"
-    assert c["tools.microsoft.msbuild"].nonexist is None
-    assert c["nonexist"].nonexist is None
+    assert c["tools.microsoft.msbuild:verbosity"] == "minimal"
+    assert c["user.company.toolchain:flags"] == "someflags"
+    assert c["tools.microsoft.msbuild:nonexist"] is None
+    assert c["nonexist:nonexist"] is None
     # bool
     assert bool(c)
     assert not bool(ConfDefinition())
@@ -71,11 +71,12 @@ def test_conf_error_per_package():
 def test_conf_error_uppercase():
     text = "tools.something:Verbosity=minimal"
     c = ConfDefinition()
-    with pytest.raises(ConanException, match=r"Conf key 'Verbosity' must be lowercase"):
+    with pytest.raises(ConanException, match=r"Conf 'tools.something:Verbosity' must be lowercase"):
         c.loads(text)
     text = "tools.Something:verbosity=minimal"
     c = ConfDefinition()
-    with pytest.raises(ConanException, match=r"Conf module 'tools.Something' must be lowercase"):
+    with pytest.raises(ConanException,
+                       match=r"Conf 'tools.Something:verbosity' must be lowercase"):
         c.loads(text)
 
 
@@ -83,4 +84,4 @@ def test_parse_spaces():
     text = "core:verbosity = minimal"
     c = ConfDefinition()
     c.loads(text)
-    assert c["core"].verbosity == "minimal"
+    assert c["core:verbosity"] == "minimal"