How does ownership work with structs

Ownership of a struct is determined by the ownership of its fields: if any field owns data (like a String), the struct owns that data, and moving the struct moves all its fields. When you assign a struct to a new variable, the entire struct is moved, invalidating the original variable unless the fields implement Copy.

struct User {
    username: String,
    active: bool,
}

fn main() {
    let user1 = User {
        username: String::from("alice"),
        active: true,
    };
    let user2 = user1; // user1 is now invalid
    // println!("{}", user1.username); // Error: value borrowed here after move
    println!("{}", user2.username); // Works
}

Ownership means the struct is responsible for cleaning up the memory used by its parts. If you give the struct to someone else, you lose access to it, just like handing over a physical object. This prevents two parts of your code from trying to use or delete the same data at the same time.