There are crazy amounts of different muscles in the human body. For the purposes to making gains, there are a few groups to keep in mind.
The groups are the following:
The Back is separated further into the TRAPS, MID BACK, and LOWER BACK. The traps are muscles that attach to the neck and run up and down the back. The mid back
consists of Rhomboids and Lats (and other smaller ones). Lats are sometimes referred to as “WINGS”.
The Chest is separated further into the UPPER CHEST and LOWER CHEST (some believe in the MIDDLE CHEST).
The Shoulders (also known as deltoids) are separated into THREE HEADS which are FRONT, LATERAL, AND REAR.
The Biceps are located at the front of the arm; they too are separated. Biceps have two heads: an INNER HEAD and OUTER HEAD.
The Triceps are located at the back of the arm; the triceps contain three heads: LONG, MEDIAL, and LATERAL HEAD. The long head is the part of the tricep that is
closest to the body. The three heads form together to make a “HORSESHOE” shape.
The Forearms are located between the wrist and elbow joints. The forearms are separated into FLEXORS and EXTENSORS. The contraction of two parts depends on the
The Abs contain an 3 main portions (one inner portion). The portions are UPPER, LOWER, and OBLIQUES. The obliques are the muscles of the side of the stomach.
The Thigh muscles contain the QUADS (front of thighs), HAMSTRINGS (back of the thighs), AND GLUTES (the butt).
The Calves are located between the ankle and knee joints. The calves contain two distinctions: the GASTROC and SOLEUS.
Hope this information was of use.