Thank you very much

To enclose means to put something inside something else. Usually it refers to putting something inside an envelope or package alongside a letter. ie "enclosed you will find a photo of me". To attach means to add on. It can be used in a variety of different ways. Often people use it in regards to adding documents or photos on to emails. ie "attached is my resume". Enclosed is probably the more formal of the too, but in my experience, people don't use it much outside of letters.