Disk - Sector (Physical block)

> I/O - (Input/Output|Read/Write) - Data Access > Drive (Secondary Storage)

Table of Contents

1 - About

Block on a disk.

On Macintosh and UNIX drives, sectors usually are grouped into cluster (logical blocks) that function as the smallest data unit permitted. Since these blocks often are defined as a single sector, the terms block and sector are sometimes used interchangeably in this context.

In essence, the sectors are numbered 0, 1, 2, etc. up to (N-1), where N is the number of sectors on the disk.

The master boot record (MBR) and the boot sector are two disk sectors that are critical to the startup process.