Anatomically, the joints connect the bones of the skeleton in a way that permits movement in certain directions. For every joint there is a limit in every direction it allows. The main limbs are mostly independent from another. However there are also some limbs that influence in certain ways the positions of other limbs. This is for anatomical reasons such as the arrangement of ligaments.
Typical human poses are standing, sitting, kneeling, lying, on all fours, etc. These are very broad terms, however. There is an infinity of pose variations and combinations.
Standing poses are called stances.