When it comes to training, there are many variations that can be done depending on the goals of the person. There are some common terms that can be heard around the training environment as lower body push, upper body pull, HIIIT, etc, which refer to the kind of movements that the training session will be focused on for the day.
Another way to look at this is with the supersets. The concept of a superset is to perform 2 exercises back to back, followed by a short rest (but not always). This effectively doubles the amount of work you are doing, whilst keeping the recovery periods the same as they are when you complete individual exercises. Normally, a superset will be made of two different muscle groups, that way, an exercise can be performed during the “resting time” of the other muscle group and vice-versa, hence applying the idea of double the amount of work.
A common idea of superset can be, for example, doing chest press (push) and back rows (pull) within the same set, being these two, opposite muscle groups, however, not all the push and pull movements should be worked together even being technically two different motions. An example of this is training shoulders and biceps on the same day, many people want to train “arms” only on one day, but, this can be contraindicated.
How the bicep is aligned, attaching to the scapulae through the short and long-head tendons. So, to get to the attachment point, the muscle tissue and tendons must pass under a lot of shoulder tissue and enter the space under the acromion process.