Learn how to use the Unix commands to move and edit and control your files. Do NOT depend on the file manager to do this work for you. You can use the file manager for small personal files, but for large data sets, use the Unix commands for working with files. Here is a place where you can find information about files. This will help you avoid disk quota problems in your own account, as well as helping to avoid filling the scratch disk and causing other users problems.
Zip compresses the contents of a file so that the disk space required to store it is much smaller.
If you are already over your disk quota, you might not have enough space to create the zipped file and keep the original file. This means that if you did not change the unzipped file during your work, you do not need to zip it back again when you are done since you already have a zipped copy. You can remove the unzipped file. It has a couple of differences. The first is that is compresses better.