What is propagating succulents? It's when you take one leaf or piece (depending on the plant) of a succulent and you nurture it until it grows roots and is able to grow a whole new plant! Succulents, in my opinion, are the easiest to do this with. Here are some picture of succulents and cacti that I will propagate.
This is a close up of the bigger "pieces" of succulents I've used to propagate
This is a close up of a cacti leaf. I believe it is called "Bunny Cacti" but please fact check me if you know the name!
This leaf you can see is already growing roots! This one should be easy to grow into another plant soon.
This is a fuzzy leaf that was part of a "Panda plant". Those succulents are cool because you can actually cut the leaf into smaller pieces and they each will have a chance to propagate.
With most succulent leaves they have to propagate at the base so you have to be careful when taking them off that you do it gently.