Swapping away from Sequence Render I rendered an animation and then placed it into the video sequence editor to test it, and rendered that as a video.

Now I want to render a second animation (in other words, keep working), but when I press render animation, it's still using the sequence render option? (Rendering it as pngs). I was wondering how to switch between sequence render and animation render properly?
You can turn Sequencer render on and off, as well as the compositor, by toggling these properties in the Scene Render Properties panel. 



You can choose to render in frame sequence or a video codec here. All you do is feed a different source to the render engine.