Using threads: 1. Tell the O/S to decide which order all your tasks execute (Wow great I don't need to worry about all that). 2. Oops, now we don't know what

Using threads: 1. Tell the O/S to decide which order all your tasks execute (Wow great I don't need to worry about all that). 2. Oops, now we don't know what order tasks will execute, so we have to program a whole heap of synchronization code. OR Do it yourself: 1. Program everything, so you know which order things occur, and don't need to worry about synchronization.