What do Tech Points do in Chrono Trigger?
Solution 1:
"Tech Points" are similar to experience, but they help to unlock more of the techs (and/or spells) each character has access to. Unlike in other games, you don't learn techs based on your level.
In the "Tech" menu, you'll see a list of the techs each character can learn, and you can see how many more TP it will take to learn the next one on the list. Confusingly, these are referred to as "Skill Points" in the tech menu.