Interchangeable
Part of speech: adjective
Definition: Freely substitutable. May be swapped at will.
Example sentence: I do believe that Raw, SmackDown, and NXT are the three brands, and I think that people can come from Raw or SmackDown to NXT, and I think that people from NXT can go to Raw or SmackDown. It's very interchangeable.
Symmetric
Part of speech: adjective
Definition: Symmetrical.Of a relation R on a set S, such that xRy if and only if yRx for all members x and y of S (that is, if the relation holds between any element and a second, it also holds between the second and the first).