I've just moved up from an old Mackie 1202 mixer to a Yamaha MG16. In going through the manual I'm confused by two things. One is Yamaha's use of the term, "Effector." It seems to used to describe some kind of input/output device but I'm not sure what. It's shown in three places. Can someone give me a hint as to how they are using the term?

Another question is that I use the M-Audio Delta 44 sound card. There are 2 stereo inputs and 2 stereo outputs. Where do these connect to the Yamaha?