Wrecking bar is a general term for various tools that are used to pry wood apart and to remove nails.
The crowbar and the pinch bar are both types of wrecking bars. These have flattened metal claws that can be used to pry wood apart. The claws have V’s cut into them so that they can be used as nail pullers.
Another type of wrecking bar is a rip bar. These have slightly rounded tips that provide a little more leverage than the other types mentioned when it is inserted between pieces of nailed wood.
All three types of wrecking bars are extremely useful for prying nailed boards apart and dismantling platforms.