From: The Frozen Tundra of MN
A little explanation for your younger readers:
Waaaaay back in the day, like, the year 2003 and before, cameras had stuff called "film". This "film" reacted to the light coming through the lens and captured a picture. There would usually be 24 pictures you could take on one "roll" of "film", but sometimes more, and sometimes less. Most cameras would count how many pictures you had taken and display the number in a little window. When the entire "roll" of "film" was used up, you would take it to the store and pay them to "develop" the "film", where they would treat it with chemicals so that it wouldn't react to light anymore, and print each picture out on special paper. Then they would give you the prints and the developed film back.
Hope that helps, and wasn't too sarcastic.
Owner and President of Applied Perspective
Fine art photography and custom laser engraving.