LOOKING FOR SCREEN RECORDERS I SEE... Well here's a few AWESOME AND EPIC screen recorders
1.Screenflick: This has no lag whatsoeva and can record at a smooth 60fps WITHOUGHT lagging your computer.
Check this video to see screen fps and quality!:
2. Screenflow: This is a popular option for many youtubers like me, it does have problems if your computer isn't high performance though...
Check this video!
3. QuickTimePlayer: This can be good if you have a GOOD COMPUTER it slightly compresses the file but is also very impressive, it cannot record system audio though...
Check this video to see how GOOD this is!
If you just want to do some simple recording, Quicktime Player is a good choice for you. Free and easy to use, and it should come with your Mac. Or you might try Acethinker Free Screen Recorder, it is a free cloud based software to record computer screen without install any software in your Mac.