How does Box transfer ownership

In Rust, Box<T> transfers ownership by moving the pointer to the heap data, not the data itself. When you assign a Box<T> to a new variable, the original variable is invalidated, and the new variable becomes the sole owner of the heap-allocated value.

fn main() {
    let b1 = Box::new(5);
    let b2 = b1; // Ownership of the Box moves to b2
    // println!("{b1}"); // Error: b1 is moved
    println!("{b2}"); // OK: b2 owns the value
}

Think of Box<T> like handing someone a key to a storage unit. When you transfer the box, you are giving them the key, not moving the heavy furniture inside. The original holder no longer has access to the item, and the new holder is now responsible for it.