I have a vague understanding of actors and fault tolerance, but it's not clear to me if actors provide fault tolerance or if they just make concurrent programmi

I have a vague understanding of actors and fault tolerance, but it's not clear to me if actors provide fault tolerance or if they just make concurrent programming less error prone? Would be happy for someone to stream-of-consciousness riff about how an Erlang-like fault tolerant approach to reliability compares with a more traditional approach in theory and in practice. E.g., if you have a component that is just erroring and restarting all the time, how does the operator know that something is wrong? Do you have special monitoring? Do you look for restarts in the logs? I guess maybe what I want to know is "how does operating an erlang-ish service compare to operating a traditional service?"