Cargo is a tool that allows Rust projects to declare their various dependencies, and ensure that you'll always get a repeatable build.

To accomplish this goal, Cargo does four things: * Introduces two metadata files with various bits of project information. * Fetches and builds your project's dependencies. * Invokes rustc or another build tool with the correct parameters to build your project. * Introduces conventions, making working with Rust projects easier.

Cargo downloads your Rust project’s dependencies and compiles your project.