How to Create Threads in Rust with std

Use std::thread::spawn to create a new thread that runs a closure, then call .join() on the returned handle to wait for it to finish.

use std::thread;
use std::time::Duration;

fn main() {
    let handle = thread::spawn(|| {
        for i in 1..10 {
            println!("number {i}!");
            thread::sleep(Duration::from_millis(1));
        }
    });

    handle.join().unwrap();
}

Creating threads in Rust with std::thread establishes a separate line of execution that runs code simultaneously with your main program. This matters because it lets your application do multiple things at once, like downloading a file while keeping the user interface responsive. Think of it as hiring a second worker to handle a task while you continue with your own.