Block – Data is stored in bit areas on storage media. The bits are grouped into blocks and the blocks numbered sequentially from the start of the disk, thus providing a block addressing scheme; “Put this data in the series of blacks starting at block number 5,623,782,566.” The storage media device controller or an accessing application has to keep track of which blocks are used and which empty. An application, such as a database can use block addressing to go straight to a location in a storage device to read or write data with no intervening steps such as transiting a file and folder structure.
Virtually all storage devices group bit areas into blocks, and data organising schemes such as files and objects are overlaid on the basic block system. The storage device controller translates an object or file and folder address into a block-level address.