Does this game have movement tech? Wtf is going on

I come from BF2 and BO2, complete opposites of games in their own right, and BF4 somehow feels sweatier than both. In BF2 I pretty much wrestle my way to a kill just fine, and in BO2 I can use my cover effectively and aim around corners to gurantee myself a kill. In this game? I'm seeing people hop around like they're playing Krunker, with near 100 percent accuracy. Like is there a tutorial for this movement style or is it forbidden in most servers. If it is forbidden, how come so many servers allow it?