The amount of joseki is huge especially when one has to perform at professional level. Each situation is different and so each situation requires its own specific joseki.
Professionals often invent joseki in their games when the standard joseki are inappropriate.
This overview contains a collection of maybe some 25 joseki variations which can be considered a beginners package to be able to play Go games. The selection is not random but carefully chosen, a so called repertoire. Each main line in the corner is considered from the white and black perspective and each time appropriate choices are made. For each choice always the considerations are given which leads to the particular choice. Each joseki discussed in this overview contains an illustrative example from a professional game in which circumstances to apply the joseki.