What is the vocabulary used by fighter pilots used to communicate?
There are NATO standard terms.  For example the MiG-29 is known as a "Fulcrum." That's not the Russian name for it but the "NATO reporting name" which you can look up on Wikipedia.

There are also some standard (but not codified) terms such as "angels" meaning "thousands of feet."  And there are some standard terms such as "bent" meaning "inoperative" but I don't know how much those are used any more.

Within a certain operating area or task force, there may be specific code words used that may change from day to day.  These would not be known to anyone outside that area or task force.