I was reading about Openssh and I have the following questions:

1. What is the difference between ssh and slogin ?

2. What is the difference between scp and sftp ?

3. Does sshd (on server side) provide separate server processes to handle each client (ssh , slogin , sftp , scp) type requests or just one process for all client types ?

4. is the secure shell a standalone shell like bash ...etc or just a process that encrypt/decrypts traffic and communicate to ordinary bash process locally ?

Thanks