# Introduction In this lab, we explore mutability in Rust by examining the concept of borrowing data through mutable and immutable references using the example of a book struct with functions that demonstrate the behavior of mutable and immutable borrowing. > **Note:** If the lab does not specify a file name, you can use any file name you want. For example, you can use `main.rs`, compile and run it with `rustc main.rs && ./main`.
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