turn

順番(じゅんばん)	This is closer to the English word ‘rotation’. Used when more than two people or things are deployed in a sequence:batters in a baseball game, for instance. Kids lining up to use a slide. If you’re catering a banquet and have to put down placemats in order of:red, green, blue, pink, repeat, that’s also 順番. But 順番 is only used when the sequence keeps repeating over and over. If people are lined up for, say, Space Mountain, but they only ride it once and then go their separate ways, that’s just a 列, a line. $$$

出番(でばん)	Turn. Now it’s my turn! But it’s also commonly used in the sense of ‘chance.’ Like if the company is going to go bankrupt and only the humble janitor can save them, he’s like “Now it’s my turn to shine!” and then they make him CEO, or something. So it’s not limited to structured settings where you’re taking a number. PPP

互違い(たがいちがい)	Alternating. Used about objects. The alternating black-and-white tiles of the traditional chess board.

交互に(こうごに)	Alternating – used about humans. We take turns moving our chess pieces.