In audio and computing the term block merely refers to a segment of data. It is significant because digitized data is often stored in blocks of a predetermined size (often 512 or 1024 bytes). For example, a disk might be formatted to hold data in blocks that are 512 bytes in size. That means if you have a packet of data to be written that is 1,047 bytes long it will require 3 blocks to store it, even though the third block is technically almost empty. This empty space can not be used by any other data. This block method of data storage and retrieval is key to making it easy for computers to be able to quickly locate specific data on disks and other storage media.