5.2.2. Block-Based Addressing

Block-based addressing is much more straightforward than geometry-based addressing. With block-based addressing, every data block is given a unique number. This number is passed from the computer to the mass storage device, which then internally performs the conversion to the geometry-based address required by the device's control circuitry.
Because the conversion to a geometry-based address is always done by the device itself, it is always consistent, eliminating the problem inherent with giving the device geometry-based addressing.