Relevance of Advanced Placement courses to graduate admissions So a lot of websites recommend taking AP courses and earning college credits in advance. What exactly are advanced placement courses and where can one take them ? Why are they stressed upon; are they really all that important a factor while considering students for admission to a Master's program?
As mentioned in the comments above, the Advanced Placement (AP) program offers students the opportunity to earn college credits for courses completed during high school by successfully passing an exam of difficult comparable to that of a college course.

Directly, AP courses do not influence graduate admissions, since they are generally excluded from cumulative averages. However, they indirectly can influence master's and PhD admissions, because the ability to place out of lower-level courses can open up the possibility to complete more advanced courses in a given discipline, or allow for enough "freedom" in the course plan to allow time for graduate-level coursework. For example, I had sufficient AP credits to opt out of a number of courses as an undergraduate; as a result of this, I was able to take three different graduate-level courses plus an advanced undergraduate math elective that otherwise I would not have had time for.