The Vinyasa Sequence is the middle part of the full Sun Salutation. Often in vinyasa classes, you'll be given the option to "take a vinyasa" if you'd like to. The Vinyasa Sequence is what teachers are usually referring to when they say that, but you NEVER have to do it if you don't want to. You can always just hang out in down dog for a few breaths, come into child's pose, or take any other movements that are calling to you instead!