Upper/Lower body is a common 2 day split. It’s very good for beginners or intermediate. This is also fairly easy to design yourself. All you need to do is come up with two exercises for each upper body muscle group(any muscle group above your waist) and two exercises each for lower body.
You can do this workout more often. This is good for the person who has more days in their schedule to train and want to achieve better results.
The more days you can train(without over training and making sure you get enough rest) the better and quicker results you will get but make sure your body and schedule can allow it.
An example of this is Monday-Upper Body, Tuesday-Lower Body, Wed-Upper Body, Thursday-Lower Body and then take a day rest and start all over again. Or you can design it so you are doing Upper Body on Monday, Lower Body Tuesday, then a day rest and Upper Body Thursday and Lower Body Friday and then start all over again on Sunday or Monday.