An event is, as the name itself says, an event fired when some action, automated or not, has taken place.
Click is the event fired when the user taps button1.
A routine name is usually the name, either of the view that the routine handles, like the one above, or a user general purpose defined one.
A routine is a block of code (may be a sub or not), that executes a specific task
For x =0 to 1000
The examples above are very simplistic and should not be regarded as real world code