Tech Points are a special type of experience points in Kingdom Hearts. Tech Points are earned when Sora exploits an enemy's weakness, parries an enemy attack with an attack of their own, or uses an enemy's attack against themselves (usually deflecting some sort of projectile attack). Some common ways to earn Tech Points include the following, with examples:
The first time Sora can earn Tech Points is while fighting Darkside. Performing a finisher on its head will earn two Tech Points. There are also other ways to earn Tech Points. Sora can earn Tech Points while fighting their friends on Destiny Islands; when Wakka throws his Blitzball, Sora can attack to reflect it back at them. Soon after, when fighting Leon in Traverse Town, Sora can again earn Tech Points. When Leon fires a fireball, if Sora times their attack to deflect the fireball back at him, Leon will be stunned and Sora will earn two Tech Points - one for blocking the attack and another for hitting Leon with it.
Tech Points are also present in Kingdom Hearts III Gummi ships. If you dodge an attack just as it's about to hit you, you will gain Tech Points.