O-Ring Seal

The combination of a gland and an O-Ring providing a fluid-tight closure.
Moving (Dynamic) – O-Ring seal where there is relative motion between some gland parts and the O-Ring (oscillating, reciprocating, or rotary motion).
Non-moving (Static) – O-Ring seal in where there is no relative motion between any part of the gland and the O-Ring (distortion from fluid pressure or swell from fluid immersion is excluded).