The difference
A static seal has no relative motion across the sealing interface — the parts it seals do not move against the ring. A dynamic seal must accommodate motion, such as a reciprocating rod or piston.
What motion changes
Dynamic service drives lower squeeze (to limit friction and heat), tighter surface finish on the moving face, careful lubrication, and attention to the clearance gap. The same nominal ring that is comfortable as a static seal may run hot, wear or extrude when moving.
Design implication
Pick the calculator that matches the duty. The radial static tool targets static squeeze and fill; the radial dynamic tool adds friction, surface finish and lubrication checks for reciprocating service.