Rust's dynamic traits are like Java or C# Interfaces.

Rust's Static traits are used like C++ templates but with more compiler checks and guidance.

In both cases, you can separate the code that implements the trait from the class itself (like a partial class). In Rust you can also retroactively declare a trait and then implement that trait for a class you like (even someone else's class, or a standard class).

you're right, Scala has also type classes, though. Generics, traits, variance, etc., are all quite sophisticated in Scala. I wouldn't say it's taken from Rust. The idea had been there for a while.