finished the last project and now I am trying my first sweater. It is a pretty straight forward pattern - you make the back, the front, the sleeves and then bring it together. I think I can do that however, they use the term “cast off” x number of stitches… What is cast off? Do you put stitches on a stitch holder or another needle or what?
As always - thanks so much for all the experienced advice! This newby really appreciates your help!
Cast off?
“Cast on” = start the project.
“Cast off” = end the project. Americans also use the term “Bind off.” But my English grandmother said “cast off,” so that one sounds more natural to me! 
DCM
Yeah. They mean bind-off. I’m assuming you know how to do this since you are saying that you’ve already finished a project before, you have probably already done a bind off.
If you aren’t sure of how to do a bind off, then there are videos in the video section at the top of the page that will show you how to do this.