How can recess appointments allow the president to bypass the confirmation process?

The recess appointment was adopted to keep the government functioning. They wanted to avoid the government stalling or freezing because an appointment had not been made or confirmed because Congress was away. This can be a great way for the President to also get a person into a position that they might not have received because they wouldn't have been confirmed, often due to the opposing party having control of the Senate. 

Very useful. it is to learn because history repeats itself so learning about it those mistakes not happen again.