'Importing' means getting the clips and other material you need into your
project.
Some programs let you organise your clips into separate folders, which can
help if you have a lot of clips.
You may also be able to rename clips. This is a good idea if a lot of your
clips look similar.
If you want to use different parts of the same clip, you can make 'subclips'
or 'split' the clip.