What does Cargo do for a Rust project?

Cargo is Rust's build system and package manager. It handles dependency resolution, compilation, testing, documentation, benchmarking and publishing, which keeps projects consistent.

• Cargo.toml declares the package: name, version, edition, dependencies, features and build profiles.
• Cargo.lock pins exact dependency versions for reproducible builds. Commit it for binaries, not necessarily for libraries.
• src/main.rs builds a binary crate; src/lib.rs builds a library crate. Dependencies come from crates.io, a git URL or a local path.

[package]
name = "demo"
version = "0.1.0"
edition = "2021"

[dependencies]
serde = { version = "1", features = ["derive"] }

Common commands are cargo build, cargo run, cargo test, cargo clippy for lints, cargo fmt and cargo doc. Workspaces let several crates share one lockfile and target directory. This tooling is a major reason Rust projects look uniform across teams.