Auto merge of #6321 - ehuss:glossary, r=dwijnand

Add a glossary.

Closes #4392, closes #3380.

src/doc/src/SUMMARY.md

@@ -30,3 +30,4 @@
     * [Unstable Features](reference/unstable.md)
 
 * [FAQ](faq.md)
+* [Appendix: Glossary](appendix/glossary.md)

src/doc/src/appendix/glossary.md

@@ -0,0 +1,178 @@
+# Glossary
+
+### Artifact
+
+An *artifact* is the file or set of files created as a result of the
+compilation process. This includes linkable libraries and executable binaries.
+
+### Crate
+
+Every target in a package is a *crate*. Crates are either libraries or
+executable binaries. It may loosely refer to either the source code of the
+target, or the compiled artifact that the target produces. A crate may also
+refer to a compressed package fetched from a registry.
+
+### Edition
+
+A *Rust edition* is a developmental landmark of the Rust language. The
+[edition of a package][edition-field] is specified in the `Cargo.toml`
+manifest, and individual targets can specify which edition they use. See the
+[Edition Guide] for more information.
+
+### Feature
+
+A [*feature*][feature] is a named flag which allows for conditional
+compilation. A feature can refer to an optional dependency, or an arbitrary
+name defined in a `Cargo.toml` manifest that can be checked within source
+code.
+
+Cargo has [*unstable feature flags*][cargo-unstable] which can be used to
+enable experimental behavior of Cargo itself. The Rust compiler and Rustdoc
+also have their own unstable feature flags (see [The Unstable
+Book][unstable-book] and [The Rustdoc Book][rustdoc-unstable]).
+
+### Index
+
+The index is the searchable list of crates in a registry.
+
+### Lock file
+
+The `Cargo.lock` *lock file* is a file that captures the exact version of
+every dependency used in a workspace or package. It is automatically generated
+by Cargo. See [Cargo.toml vs Cargo.lock].
+
+### Manifest
+
+A [*manifest*][manifest] is a description of a package or a workspace in a
+file named `Cargo.toml`.
+
+A [*virtual manifest*][virtual] is a `Cargo.toml` file that only describes a
+workspace, and does not include a package.
+
+### Member
+
+A *member* is a package that belongs to a workspace.
+
+### Package
+
+A *package* is a collection of source files and a `Cargo.toml` manifest which
+describes the package. A package has a name and version which is used for
+specifying dependencies between packages. A package contains multiple targets,
+which are either libraries or executable binaries.
+
+The *package root* is the directory where the package's `Cargo.toml` manifest
+is located.
+
+The [*package id specification*][pkgid-spec], or *SPEC*, is a string used to
+uniquely reference a specific version of a package from a specific source.
+
+### Project
+
+Another name for a [package](#package).
+
+### Registry
+
+A *registry* is a service that contains a collection of downloadable crates
+that can be installed or used as dependencies for a package. The default
+registry is [crates.io](https://crates.io). The registry has an *index* which
+contains a list of all crates, and tells Cargo how to download the crates that
+are needed.
+
+### Source
+
+A *source* is a provider that contains crates that may be included as
+dependencies for a package. There are several kinds of sources:
+
+- **Registry source** — See [registry](#registry).
+- **Local registry source** — A set of crates stored as compressed files on
+  the filesystem. See [Local Registry Sources].
+- **Directory source** — A set of crates stored as uncompressed files on the
+  filesystem. See [Directory Sources].
+- **Path source** — An individual package located on the filesystem (such as a
+  [path dependency]) or a set of multiple packages (such as [path overrides]).
+- **Git source** — Packages located in a git repository (such as a [git
+  dependency] or [git source]).
+
+See [Source Replacement] for more information.
+
+### Spec
+
+See [package id specification](#package).
+
+### Target
+
+The meaning of the term *target* depends on the context:
+
+- **Cargo Target** — Cargo packages consist of *targets* which correspond to
+  artifacts that will be produced. Packages can have library, binary, example,
+  test, and benchmark targets. The [list of targets][targets] are configured
+  in the `Cargo.toml` manifest, often inferred automatically by the [directory
+  layout] of the source files.
+- **Target Architecture** — The OS and machine architecture for the built
+  artifacts are typically referred to as a *target*.
+- **Target Triple** — A triple is a specific format for specifying a target
+  architecture. See the [clang documentation] for details. Triples may be
+  referred to as a *target triple* which is the architecture for the artifact
+  produced, and the *host triple* which is the architecture that the compiler
+  is running on. The target triple can be specified with the `--target`
+  command-line option or the `build.target` [config option].
+- **Target Directory** — Cargo places all built artifacts and intermediate
+  files in the *target* directory. By default this is a directory named
+  `target` at the workspace root, or the package root if not using a
+  workspace. The directory be changed with the `--target` command-line option,
+  the `CARGO_TARGET_DIR` [environment variable], or the `build.target-dir`
+  [config option].
+
+### Test Targets
+
+Cargo *test targets* generate binaries which help verify proper operation and
+correctness of code. There are two types of test artifacts:
+
+* **Unit test** — A *unit test* is an executable binary compiled directly from
+  a library or a binary target. It contains the entire contents of the library
+  or binary code, and runs `#[test]` annotated functions, intended to verify
+  individual units of code.
+* **Integration test target** — An [*integration test
+  target*][integration-tests] is an executable binary compiled from a *test
+  target* which is a distinct crate whose source is located in the `tests`
+  directory or specified by the [`[[test]]` table][targets] in the
+  `Cargo.toml` manifest. It is intended to only test the public API of a
+  library, or execute a binary to verify its operation.
+
+### Workspace
+
+A [*workspace*][workspace] is a collection of one or more packages that share
+common dependency resolution (with a shared `Cargo.lock`), output directory,
+and various settings such as profiles.
+
+A [*virtual workspace*][virtual] is a workspace where the root `Cargo.toml`
+manifest does not define a package, and only lists the workspace members.
+
+The *workspace root* is the directory where the workspace's `Cargo.toml`
+manifest is located.
+
+
+[Cargo.toml vs Cargo.lock]: guide/cargo-toml-vs-cargo-lock.html
+[Directory Sources]: reference/source-replacement.html#directory-sources
+[Local Registry Sources]: reference/source-replacement.html#local-registry-sources
+[Source Replacement]: reference/source-replacement.html
+[cargo-unstable]: https://doc.rust-lang.org/nightly/cargo/reference/unstable.html
+[clang documentation]: http://clang.llvm.org/docs/CrossCompilation.html#target-triple
+[config option]: reference/config.html
+[directory layout]: reference/manifest.html#the-project-layout
+[edition guide]: https://rust-lang-nursery.github.io/edition-guide/
+[edition-field]: reference/manifest.html#the-edition-field-optional
+[environment variable]: reference/environment-variables.html
+[feature]: reference/manifest.html#the-features-section
+[git dependency]: reference/specifying-dependencies.html#specifying-dependencies-from-git-repositories
+[git source]: reference/source-replacement.html
+[integration-tests]: reference/manifest.html#integration-tests
+[manifest]: reference/manifest.html
+[path dependency]: reference/specifying-dependencies.html#specifying-path-dependencies
+[path overrides]: reference/specifying-dependencies.html#overriding-with-local-dependencies
+[pkgid-spec]: reference/pkgid-spec.html
+[rustdoc-unstable]: https://doc.rust-lang.org/nightly/rustdoc/unstable-features.html
+[targets]: reference/manifest.html#configuring-a-target
+[unstable-book]: https://doc.rust-lang.org/nightly/unstable-book/index.html
+[virtual]: reference/manifest.html#virtual-manifest
+[workspace]: reference/manifest.html#the-workspace-section