Packages
A package is a collection of one or more crates that provide a set of
functionalities. It includes a Cargo.toml
file that outlines how to build
those crates. A package can contain multiple binary crates, but only one library
crate at most. However, a package must contain at least one crate, whether it's
a library or binary crate.
Refer to the section on Packages and Crates in the Rust documentation.