I am looking at these PCB mount terminal blocks- .25 pitch, .325 pitch, .375 pitch.... what does that mean? What is "pitch" referring to?
http://www.mouser.com/Search/ProductDetail.aspx?R=6PCV-05-006virtualkey57110000virtualkey571-814376522
http://www.mouser.com/Search/ProductDetail.aspx?R=6PCV-05-006virtualkey57110000virtualkey571-814376522