What's the difference between a peel and a facial mask ?

Someone may confuse about whether a mask and a peel serve the same purpose or if they are completely different. Also, if they are different, how often should they be used?

TIP: Facial masks control excessive oil and helps tighten pores.Facial peels remove dead skin cells which can make your complextion look dull.You can use a facial mask twice a week but only have a facial peel once a month!

They are both great!