Temporary files is always an issue for any operating system, which are saved when you install or uninstall any softwares, or temporary saved web pages for the cookies and saved passwords in the pages you browsed.

Deleting them in windows is pretty easier with Disk Cleanup tool but in mac, as i heard before, the terminal app can help to do it but playing in the terminal app is hard.

Here is another easier way to do so -
MacCleaner app which can help you find all the temporary files and saved pages in the mac, and lets you delete them in a single go. This can make some more space free in mac and also makes Macbook run faster when these temporary files get deleted.

You can download MacCleaner from maccleaner.com