That three percent included packages, methods, and class names. But those declarations—like starting a function with package java.lang —can only be used in certain ways.

Oracle amended its suit, which had been mired in litigation and appeals. It now names Android operating systems Gingerbread, Honeycomb, Ice Cream Sandwich, Jelly Bean, KitKat, and Lollipop.

Wondering what the lawyers and programmers are talking about in the highest-profile tech trial in years? Here's a guide to the ties between Android and Java -- and the history leading up to the case.