Blocks are a method that a designer/engineer use to group data. It's often used as an easy way to create repetitive objects, like valves and fences, but is sometimes used on data needed for the takeoff. Earthwork 4D can read data that is in blocks. Upon import, the program automatically binds and explodes the blocks to make them usable, often eliminating the need to open the file in AutoCAD before using the file.