The XLR cord is the standard mic cord for plugging things into the mixer. It has 3 pins with a male and female end.
Quarter Inch Cord
The 1/4 (quarter) inch cord is usually used by instruments when plugging into a mixer.
Eighth Inch Cord
The 1/8 (eighth) inch cord is the plug that your headphones use on your cell phone or mp3 player.
RCA connectors are the red and white plugs. These are used for music and usually have an 1/8 plug on the other end. Red is for the right channel and white is for the left channel.