pure instruction -> teaching through playing -> friendly match -> competitive match
Let's use a card game as an example.
Pure instruction: Both players play with their cards visible to each other, and the teacher coaches rules and strategy as they play.
Teaching through playing: The hands are now private, but the teacher will tell the student if they're making bad moves and allow do-overs. The teacher may also set up situations for the student to take advantage of.
Friendly match: The teacher is playing against the student. No coaching is given. But, nit-picky procedural rules are not always followed. (You've set that card down and your hand left it, you can't pick it up again).
Competitive match: Rules are followed to the letter.