For each chord, there exist alternative ways to play them. In some cases, one can play inversions instead of the normal chord. I use inversions in order to fit my fingers more comfortably on the keyboard.
For more about Chords and fingering, see blog.
Using the Piano Chords Dictionary, I have created a minimum set of chords which could be used as a base for learning to play piano. Left hand plays chords, and right hand the melody.
With this minimal set, one can play many songs. For more advanded, one can learn step by step to play chords with 4 fingers (ie. X7 and Xm7 chords).