---
tags:
  - Linux
  - Operating_Systems
  - disks
  - devices
---

# What are disks?

A disk is a mass storage [block_device](/Operating_Systems/Devices.md) which we can write to and read from.

## SCSI
* Small Computer System Interface, responsible for handling disk access on most Linux systems.
* It is a protocol that allows communicaton between printers, scanners and other peripherals in addition to harddisks. 
## Disk schematic
The following diagram represents the basic anatomy of a disk device.

![](/img/harddisk.png)


* A disk is divided up into [partitions](/Operating_Systems/Disks/Partitions.md) which are subsections of the overall disk. The kernel presents each partition as a [block device](/Operating_Systems/Devices.md#Devices.md) as it would with an entire disk.
* The disk dedicates a small part of its contents to a **partition table**: this defines the different partitions that comprise the total disk space. 
* The **filesystem** is a database of files and directories: this comprises the bulk of the partition and is what you interact with in [user space](/Operating_Systems/User_Space.md) when reading and writing data.