There are literally hundreds of chords, but there are only 5 basic types of chords and all other chords are combinations and extensions of the basic chords. The 5 basic chord types are major, minor, 7th, diminished and augmented. My chord piano series presents all five types of chords.
There are 12 different keys on a piano from one octave to another and a major, minor, 7th, diminished or augmented chord can be constructed on each key. So 5 types each on 12 keys equals 60 chords.
(Since each black key has two names, example: C# and Db, two chords can be constructed from a black key, though they both will have the same piano keys in them. That totals 17 major chords. In other words, a C# chord sounds exactly like a Db chord and both chords have the same piano keys. A Db chord is much more common than a C# chord.)
All pop piano music (pop piano is any music that is not classical, and in this case, also jazz) use standard chords. These chords are C, Db, D, Eb, E, F, F#, Gb, (F# and Gb are the same piano key and are used equally often, so they are both indicated here), G, Ab, A, Bb, B. That's a total of 13, since F# and Gb are the same key. The chord books in my series use these standard 13 chords.