Taking one picture everyday for one full year. You can also make one video everyday for a year, made in one sitting or out of clips they take throughout the day. It can also be called a vlog, or a year-long vlog.
Shay: So Charles are you going to copy me and do Project 365?
Charles: Yeah, Why?
Shay: No reason... other than that is awesome!
Charles: Yeah, I know, that is why I am doing it, ha, that's what she said!