Built-in Mac screenshot feature (very simple and quick), Screenflow for video (very comprehensive, plenty of features). I have heard that Capto is good, but I have never tried it (though I have SetApp, and it is one of the programs on that).
On Mac, I often use the video screen capture built into the QuickTime video player. After trimming it, I drop the QT file onto Gifski to build an animated GIF.
Screenflow is a bit like Scrivener for Screencasts. It is fairly easy to get going with and make simple videos with, but it also has a lot of really powerful tools if you want to make more sofisticated videos. iMovie, which is the built-in Apple app for making videos can be used for some videos but with Screenflow you can easily add greenscreen effects (chroma key) combine input from different videos, screens or cameras, etc.