What is the different between cavalry and calvary?

Calvary is the name of a place, the hill where Christ was said to be crucified.

Cavalry is a term used to describe horse-mounted soldiers, although modern cavalry regiments are mechanized. It comes from the Italian word 'cavallo' meaning horse. Also from cavallo comes the word cavaliere, meaning knight (or mounted soldier), which in french is 'chevalier', from which comes the word 'chivalry' in English.