It is important to retain about 25% free space on your Mac hard drive for it to operate at peak efficiency. That means removing large files at times to free up space. There are some free Apps for the Mac that show you large file sizes. One of them is OmniDiskSweeper which I use, but there are others. This article mentions a few Apps and how they work. It is a good idea to use at least one of these from time to time to manage your hard drive space.