A Basic Understanding of Tracks & Sectors
The platters inside a hard drive are structured to facilitate the storage and retrieval of data. Each platter is divided into concentric rings called "Tracks". There are thousands of tracks on each platter. They look like the rings of a very, very old tree.
Each track is divided into sectors. A sector, as a rule, holds 512 bytes of data, this is usually the minimum quantity of information which is independently addressable for storage on a hard drive disk. Today, hard drive platters have thousands of sectors in a single track.