Rust: What is the difference between static dispatch and dynamic dispatch?

Static — compile-time. Dynamic — runtime.

Static:

• Monomorphization.
• No overhead.
• Larger binary.

Dynamic:

• Virtual table.
• Indirect call.
• Smaller binary.

1// Static dispatch
2fn print<T: Display>(item: &T) {
3    println!("{}", item);
4}
5
6// Dynamic dispatch
7fn print(item: &dyn Display) {
8    println!("{}", item);
9}

Key: Static for performance, dynamic for flexibility.