Please write the solution in a computer handwriting and not in handwriting because the handwriting is not clear

Required questions in the picture

It is also required to mention the references that were used to extract the answers to the questions such as websites or books with the link for the reference

so I hope to solve each question with the reference and the link

1- What is RPC, and why do we need it? 2- How do you enumerate Windows? 3- How do you enumerate Linux