Explain the process Bob should use if he wants to send a confidential message to Alice using asymmetric cryptography

Explain the process Bob should use if he wants to send a confidential message to Alice using asymmetric cryptography.
Explain the process Alice would use to decrypt the message Bob sent in question one.
Explain the process Bob should use to sign a message to Alice digitally.
Explain the process Alice should use to verify the digital signature on the message from Bob in question three