Short answer. A static pole does not rotate. A spinning pole does. The same move feels different on each, because on spin the pole carries momentum and on static you have to create it yourself.
Static
The pole is locked. It is the usual place to learn a hold, a climb and the shape of a spin, because the pole will not run away from your hands. Conditioning that involves hanging is also clearer when the pole is still. Many beginner classes spend most of the hour here.
Spinning
A bearing lets the pole rotate. Once you and the pole are turning, the timing of a grip change is different: you are managing speed, not only strength. Flow looks different on spin. So does a badly timed hand. Teachers often introduce spin after a student can already do the move, slowly, on static.
Neither setting is the “real” one. Performances and classes use both. Competition codes sometimes specify the setting. A weekly class in Brussels will say, or the teacher will set the pole before you start.
At Flow Factory
The studio has 9 stainless poles, 7 of 45 mm and 2 of 40 mm. They are not permanently one or the other. Each can be switched between spin and static with an x-lock, also called a quick spin: the ring is lifted and turned until it clicks. Students are not asked to improvise that mechanism in a first class. The teacher sets it. This switching system is Flow Factory’s. Other Brussels studios have not published their pole hardware on the pages checked for this guide, so this page does not describe theirs.
Diameter changes how a hand closes. A 40 mm pole is smaller in the hand than a 45 mm pole. It is a preference and a training variable, not a rank.