diff --git a/activejob/test/support/integration/adapters/backburner.rb b/activejob/test/support/integration/adapters/backburner.rb
index 19209d6270d1d..597cd2a6fb109 100644
--- a/activejob/test/support/integration/adapters/backburner.rb
+++ b/activejob/test/support/integration/adapters/backburner.rb
@@ -8,7 +8,7 @@ def setup
       config.logger = Rails.logger
     end
     unless can_run?
-      puts "Cannot run integration tests for backburner. To be able to run integration tests for backburner you need to install and start beanstalkd.\n"
+      puts "Cannot run integration tests for Backburner. To be able to run integration tests for Backburner you need to install and start beanstalkd.\n"
       status = ENV["BUILDKITE"] ? false : true
       exit status
     end
diff --git a/activejob/test/support/integration/adapters/queue_classic.rb b/activejob/test/support/integration/adapters/queue_classic.rb
index eaaef88392cff..c17400f3e5220 100644
--- a/activejob/test/support/integration/adapters/queue_classic.rb
+++ b/activejob/test/support/integration/adapters/queue_classic.rb
@@ -40,7 +40,7 @@ def start_workers
     end
 
   rescue PG::ConnectionBad
-    puts "Cannot run integration tests for queue_classic. To be able to run integration tests for queue_classic you need to install and start postgresql.\n"
+    puts "Cannot run integration tests for QueueClassic. To be able to run integration tests for QueueClassic you need to install and start PostgreSQL.\n"
     status = ENV["BUILDKITE"] ? false : true
     exit status
   end
diff --git a/activejob/test/support/integration/adapters/resque.rb b/activejob/test/support/integration/adapters/resque.rb
index d12c696c1be22..b9dcb7c0cf87f 100644
--- a/activejob/test/support/integration/adapters/resque.rb
+++ b/activejob/test/support/integration/adapters/resque.rb
@@ -6,7 +6,7 @@ def setup
     Resque.redis = Redis::Namespace.new "active_jobs_int_test", redis: Redis.new(url: ENV["REDIS_URL"] || "redis://127.0.0.1:6379/12")
     Resque.logger = Rails.logger
     unless can_run?
-      puts "Cannot run integration tests for resque. To be able to run integration tests for resque you need to install and start redis.\n"
+      puts "Cannot run integration tests for Resque. To be able to run integration tests for Resque you need to install and start Redis.\n"
       status = ENV["BUILDKITE"] ? false : true
       exit status
     end
diff --git a/activejob/test/support/integration/adapters/sidekiq.rb b/activejob/test/support/integration/adapters/sidekiq.rb
index 5309391604ff6..023cadc8e7b8e 100644
--- a/activejob/test/support/integration/adapters/sidekiq.rb
+++ b/activejob/test/support/integration/adapters/sidekiq.rb
@@ -9,7 +9,7 @@ module SidekiqJobsManager
   def setup
     ActiveJob::Base.queue_adapter = :sidekiq
     unless can_run?
-      puts "Cannot run integration tests for sidekiq. To be able to run integration tests for sidekiq you need to install and start redis.\n"
+      puts "Cannot run integration tests for Sidekiq. To be able to run integration tests for Sidekiq you need to install and start Redis.\n"
       status = ENV["BUILDKITE"] ? false : true
       exit status
     end
diff --git a/activejob/test/support/integration/adapters/sneakers.rb b/activejob/test/support/integration/adapters/sneakers.rb
index add755b39955a..0848c883a38e3 100644
--- a/activejob/test/support/integration/adapters/sneakers.rb
+++ b/activejob/test/support/integration/adapters/sneakers.rb
@@ -17,7 +17,7 @@ def setup
                         pid_path: Rails.root.join("tmp/sneakers.pid").to_s,
                         log: Rails.root.join("log/sneakers.log").to_s
     unless can_run?
-      puts "Cannot run integration tests for sneakers. To be able to run integration tests for sneakers you need to install and start rabbitmq.\n"
+      puts "Cannot run integration tests for Sneakers. To be able to run integration tests for Sneakers you need to install and start RabbitMQ.\n"
       status = ENV["BUILDKITE"] ? false : true
       exit status
     end
diff --git a/activerecord/lib/active_record/sanitization.rb b/activerecord/lib/active_record/sanitization.rb
index beb48174edcd7..d1b3dbce0b48e 100644
--- a/activerecord/lib/active_record/sanitization.rb
+++ b/activerecord/lib/active_record/sanitization.rb
@@ -212,7 +212,7 @@ def replace_bind_variable(value, c = connection)
 
         def replace_named_bind_variables(statement, bind_vars)
           statement.gsub(/([:\\]?):([a-zA-Z]\w*)/) do |match|
-            if $1 == ":" # skip postgresql casts
+            if $1 == ":" # skip PostgreSQL casts
               match # return the whole match
             elsif $1 == "\\" # escaped literal colon
               match[1..-1] # return match with escaping backlash char removed
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 64a9dea4e149d..611d3454c798a 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -122,7 +122,7 @@ def test_schema_dump_includes_limit_constraint_for_integer_columns
       assert_match %r{c_int_1.*limit: 2}, output
       assert_match %r{c_int_2.*limit: 2}, output
 
-      # int 3 is 4 bytes in postgresql
+      # int 3 is 4 bytes in PostgreSQL
       assert_match %r{"c_int_3"(?!.*limit)}, output
       assert_match %r{"c_int_4"(?!.*limit)}, output
     elsif current_adapter?(:Mysql2Adapter, :TrilogyAdapter)
diff --git a/activesupport/test/cache/stores/redis_cache_store_test.rb b/activesupport/test/cache/stores/redis_cache_store_test.rb
index 36a8e1d75c868..53fc32d5bdcd4 100644
--- a/activesupport/test/cache/stores/redis_cache_store_test.rb
+++ b/activesupport/test/cache/stores/redis_cache_store_test.rb
@@ -135,7 +135,7 @@ def build(**kwargs)
   class StoreTest < ActiveSupport::TestCase
     setup do
       @cache = nil
-      skip "redis server is not up" unless REDIS_UP
+      skip "Redis server is not up" unless REDIS_UP
       @namespace = "test-#{SecureRandom.hex}"
 
       @cache = lookup_store(expires_in: 60)
diff --git a/railties/lib/rails/health_controller.rb b/railties/lib/rails/health_controller.rb
index 6de04dc5ce510..57337610955b2 100644
--- a/railties/lib/rails/health_controller.rb
+++ b/railties/lib/rails/health_controller.rb
@@ -24,7 +24,7 @@ module Rails
   # The health check will now be accessible via the +/healthz+ path.
   #
   # NOTE: This endpoint does not reflect the status of all of your application's
-  # dependencies, such as the database or redis cluster. Replace
+  # dependencies, such as the database or Redis cluster. Replace
   # <tt>"rails/health#show"</tt> with your own controller action if you have
   # application specific needs.
   #