Rust: What is the difference between trait bounds and where clauses?

1fn print<T: Display + Debug>(item: T) {
2    println!("{}", item);
3}

1fn print<T>(item: T)
2where
3    T: Display + Debug,
4{
5    println!("{}", item);
6}

1fn process<T, U>(t: T, u: U)
2where
3    T: Display,
4    U: Debug + Clone,
5    <U as Iterator>::Item: Display,
6{
7    // ...
8}