From my knowledge (correct me if I'm wrong) those are actually a type of succulent in the Euphorbia genus. So, it is not a cactus, but I'm not sure of the species. It looks like a Eurphobia lactea though. (it might actually be one but I'm not an expert)

Here's a case of convergent evolution - it's cactus-like, but it's Old World (likely Africa), whereas cacti are New World. Ariocarpus (itself a species of cactus) nailed it - it's a Euphorbia. Keep it warm with some sun and water when dry, plant it in a porous soil and it will be happy.

Careful with the latex which will bleed from the plant if it's injured / cut - it can be an irritant or worse.

Thank you for your help. Ariocarpus got me pointed in the right direction. I was able to do a search and found the plants. They won't survive our winters, so will bring them in pretty soon.

Euphorbia on right is an easy one to ID, it is Euphorbia lactea. I have some of these also. There is a beautiful white form known as 'White Ghost' I hope to get one day.

The one on the left, however, is problematical. There are so many similar looking species, nailing it down is difficult. I have this one also, and have seen it identified as E. ammak, E. ingens, and others.

There are a few Euphorbiacs on this forum who may be able to help you further with this one.

Christopher

I thought the one of the left might be Euphorbia trigona, but not sure. It is hard to tell from internet pictures.

I re-potted both of them in larger pots with "cactus" mix and put them outside for the summer. I will move them into the house soon, our night time temps are starting to drop. 51 degrees last night.
Thank you for your help.

The one on left is not E. trigona, which has thinner and longer stems and branches, but as I said, it is hard to pin down exactly what it is.

Christopher