QuickTime allows you to capture your entire screen or just parts of it and also lets you capture the audio using the inbuilt microphone or the current line in device.
Additionally if you're a beginner or someone who's not that tech-savvy, this tool is perfect for you: all you have to do is to go to the File menu, then select the New Screen Recording option and press the Start Recording button whenever you're ready to start. The application isn't good enough for high-end recording, but if you're a regular user, then it will offer you everything that you need.
The easiest way to make a screen recording on a Mac is to use QuickTime Player, a tool that comes preinstalled on the operating system and that you can use without spending a single cent. You should also know that the applications in this section offer the same functionality on both Yosemite and El Capitan, so compatibility isn't going to be an issue. There's no need to pay a lot for a screen-recording tool if you won't make any money out of it, so let's begin with a couple of simple tools that should be used by beginners and those who aren't looking to impress with their video-making capabilities.