When do teams switch sides in volleyball?

Teams switch sides (change courts) at the end of every set. In the deciding set, they also switch when one team reaches 8 points (FIVB/USAV) or 8 points (NFHS).

Full Explanation

Per FIVB Rule 7.1, teams change courts after each set. In the deciding set (set 5, or set 3 in best-of-3 formats), teams also change courts when the first team reaches 8 points (the "technical timeout" in 5-set play is replaced by a side change in the 5th set under FIVB rules). The team that was receiving in the last rally of the previous set becomes the serving team in the new set, per FIVB Rule 7.3. The coin toss at the start of the match determines which team serves first and which team starts on which side.

Rulesets covered: FIVB/USAV/NFHS/NCAA  |  Rule Reference: FIVB Rule 7.1