Chapter 18: Common Collection Types

In Rust, collection types are data structures that can dynamically store multiple elements at runtime. Unlike fixed-size constructs such as arrays or tuples, Rust’s collections—Vec, String, HashMap, and others—can grow or shrink as needed. They make handling variable amounts of data safe and efficient, avoiding many pitfalls encountered when manually managing memory in C.

This chapter introduces Rust’s most commonly used collections, explains how they differ from fixed-size data structures and from manual memory handling in C, and shows how Rust provides dynamic yet memory-safe ways to manage complex data.