With respect to what?
The article clearly refers to motion with 'respict' to axis spin and orbits around the sun and galaxy. Beyond that there is motion within the "Local Group" and larger super cluster galaxy groupings.
The title doesn't make it clear that that's all they're talking about. And as you say, they go beyond those two cases themselves. So I did, too.
Any good intro astronomy course will cover all the types of motion in space and there are a LOT more than two of them... I'm a little disappointed in space.com on this one. Not criticizing you. Please don't take it that way. Cheers!