Downloading youtube video on your Mac is easy. Their are good number of Apps to do that. But the best app which I found and use is called MacX Youtube Downloader,
- click here to download the app.
- After installing open the app MacX Youtube Downloader.
- Click on Link icon as shown in image.
- Paste youtube video URL and click on Analyze
- Select the resolution and click on Ok
- Click on Download Now button which you can see on bottom right corner of the screen.
Youtube video will be downloaded on to your Mac