English and Spin

"English" and "Spin" are pretty much interchangeable terms. It's the action of putting side-spin onto the cue ball, by offsetting the contact point of the cue tip, from the vertical centerline of the cue ball.
 

"Standard" English (Spin) vs. "Backhand" English

The difference in "standard" or "parallel" english/spin, is found by comparing the manner in which the cue ball is addressed by the cue tip.

Standard english form:

The cue tip is offset, with the cue shaft being held parallel to the direction of aim.

 

Backhand english form:

Cue tip offset is achieve by pivoting the cue at the bridge hand. The movement of the "back hand", which grips the cue, determines the movement of the tip.