What's the difference between presorted first-class stamps and first-class stamps?

Question

and can you mail using one presorted first-class stamp just like you can a first-class?

Answer 1

Tom_b is basically correct. The mailer includes the bar code of the address and also (as the name implies) sorts them into zip code, address sequence prior to mailing. This makes it easier and faster for the post office and therefore they give a discount. I believe that there is also a minimum number of mailings required.

This method is also used by non-profits.

Answer 2

presorted cost less and is usually used by business'.they are barcoded on the bottom to save the po the trouble and expense of doing it.