Lateral 2
Leg-Yield

This is a sideways and forward movement where the inside legs cross in front of the outside legs.
The diagram shows leg-yield to the left and note the slight bend away from the direction of travel.
Guides on how to do it with video clips are in the How To section.
Half Pass

Again a diagonal movement where outside legs cross inside legs. The horse is bent slightly in the direction of travel and his forehand leads the haunches.
Can be performed at walk, trot and canter.
Next - other movements.