This video covers Rust's module system for managing large projects. It explains packages (created with `cargo new`), which contain binary (executable) or library crates. Crates use modules to organize code and control access (public/private) using `pub`. The video demonstrates creating packages, crates, and modules, illustrating pathing (absolute/relative) and the `use` keyword for bringing items into scope, including re-exporting and using the glob operator (`*`). It also shows how to separate module definitions into separate files.