There are ten basic types of block an offensive lineman uses. There are three Golden Rules of Blocking. First, the blocker must keep his head between the defender and the play, maintaining proper position. Second, the feet never stop moving. And third, blocks are maintained until the whistle.
The Drive Block calls for the blocker to fire out low and hard on the defender hitting him squarely between the numbers, pumping the legs vigorously and driving the defender from a specified area. During the driving motion the open hands extend and the elbows lock.
The Read Block calls for the blocker to make contact with the defender in the middle of the torso and "read" the defender. The idea is the defender will choose a shoulder to attempt to go around, and the blocker then proceeds to assist the defender in that direction.
The Position Block has the blocker position himself between the play and the defender. If the defender to be blocked is already lined up in such a manner, this block might be referred to as an Angle Block. If the defender has the superior angle on the blocker, then the blocker will attempt to "Hook" the defender. This is accomplished by making contact with and sliding the head to the outside of the defender. The blocker turns his behind to the running lane fully placing himself between the defender and the play. The hands are extended.
The Double Team Block is when two blockers block the same man usually to expose an area or isolate a defensive back with a running back.
The Trap Block is when a blocker (usually a Guard) pivots the foot furthest from the direction he is going, driving of that foot and coming down the line of scrimmage in order to trap or kick out a defender left unblocked for this very purpose. More times than not the unblocked defender will penetrate into the back field making the trap block both highly visible and effective.
The Cross Pull Block has the pulling blocker coming from his own side of the line across the Center position to the other side. The Pull Block occurs when the pulling player pulls to the same side of the line he is on, going even wider toward the side line.
The Seal Block occurs when a blocker's main objective is to seal off defensive pursuit from one side of the line of scrimmage to the other.
The Cross Block attempts to take advantage or pre existing angles at the point of attack. Which blocker "goes first" is determined by the running lane and defensive alignments and tendencies. Good communication between the offensive linemen is a must in order to properly execute a good cross block.