Ever try to get a screenshot on your Mac that includes a notification or a mouse hover menu? You need a timed screenshot for that.
I’m using Keyboard Maestro for this but there are lots of ways to get timed screenshots, including the built in Grab application. OSX Daily has an article from 2011 and an even earlier one from 2010 on the topic.
Here's my KM macro that does a little count down and snaps a screenshot to my preferred location.