ifVariable = the object you're doing the event on only. onActivate -> Self -> VCE_ifVariable ["Test"] will check the brick's "test" variable, onActivate -> Player -> VCE_ifVariable ["Test"] will check the player's.
ifValue = any object but uses a more complex setup. onActivate -> Self -> VCE_ifValue ["<var:brick:test>"] checks the brick, onActivate -> Self -> VCE_ifValue ["<var:player:test>"] checks the player's.