Friends left the audience with a bunch of jokes, unforgettable characters, and one big question: were Ross and Rachel on a break or not? The acclaimed sitcom Friends came to an end in 2004 after ten seasons, but this running gag wasn't fully resolved.
Although Friends followed the lives of Monica, Chandler, Joey, and Phoebe as well, it was the relationship of Ross and Rachel that so often provided the central arc of the series. While they ultimately ended up together, one of the moments that has stayed in the memories of fans and has sparked a lot of debate is when Ross and Rachel broke up, if they were really on a break and what the terms of this really are.
First off: Ross and Rachel were on a break. In the Friends episode literally titled “The One Where Ross and Rachel Take a Break”, it’s Rachel who says “maybe we should take a break”, with Ross understanding it as a time-out from the argument they were having, only for Rachel to say “a break from us”. But the terms of such break were never discussed, and that’s what makes fans (and the characters in the series) discuss if they were still together somehow or not.
That same night, Ross went to a bar with Chandler, Joey, and the “girl from the Xerox place”, Chloe, who makes a move on him. Chloe and Ross end up spending the night together, in part prompted by a call to Rachel in which he heard her workmate Mark’s voice on the background. They get back together the next morning only to officially break up hours later after Rachel learns that Ross spent the night with Chloe and didn’t say a word. The “we were on a break” line and overall situation became a running gag for the rest of Friends, with Ross maintaining they were in fact on a break and thus his one-night stand with Chloe was somewhat forgivable, as it meant he could be with other people. Rachel's interpretation of it was the opposite.
It’s not so much that Ross had something with Chloe or anyone else, but that it happened just hours after his argument with Rachel, and assuming she was with Mark that same night doesn’t justify what he did, which was nothing more than a revenge move. This also hurt the dynamic and relationship with the rest of the Friends group, as Ross and Rachel couldn’t stand being near each other for a while. In the end, they moved on only to get back together – but not before one last “unless we’re on a break” joke from Ross.
So yes, Ross and Rachel were on a break, but not knowing the terms of such was what made the situation a big mess that could still be felt somehow through the rest of Friends, even without the literal “we were on a break!” line. Had they discussed what this meant, their storylines would have probably been very different and some characters wouldn't have been part of them.