I'm fortunate to grow pluots as well as apriums. The pluot is 3/4 plum and 1/4 apricot. The tree bark, branches and leaves look just like a plum tree. The aprium is just the opposite, looking like an apricot tree and having 1/4 plum in it's genetic makeup.
The fruits of each are extremely high is sugar and are among the sweetest, juiciest and most flavorful of fresh fruits. The pluot fruits look like plums and are usually orange fleshed like an apricot. And the apriums look like apricots with a reddish flesh. At least the ones I grow are like that.
There are several varieties of each and I am not sure what the most common commercially grown varieties are.
Very few make it into our kitchen as they are mainly just eaten fresh.