Rust: What is the difference between channel::Sender::send and try_send?

1use tokio::sync::mpsc;
2
3let (tx, mut rx) = mpsc::channel(32);
4
5// Async send
6tx.send("hello").await.unwrap();
7
8// Immediate send
9let result = tx.try_send("hello");
10if let Err(e) = result {
11    println!("Channel full: {}", e);
12}