Perquisites are the benefits or "perks" that come along with a job. Free air travel for air hostesses? Free company car for corporate execs? Free pork for politicians? That's right, they're all perquisites.
Not to be confused with prerequisite, which happens about ninety-nine percent of the time. A prerequisite is something that must occur before something else can happen. A prerequisite of getting a job, for example, is passing the interview. Of course, for some people to take a particular job, a prerequisite is that there are suitable perquisites or privileges that come with a particular position.