various devices

Internal storage:
Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.

* Hard disk - for medium-term storage of data.
* Solid state drive - a device emulating a hard disk, but containing no moving parts.
* Disk array controller - a device to manage several hard disks, to achieve performance or reliability improvement.

Sound card:
Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade.

Networking:

Connects the computer to the Internet and/or other computers.

* Modem - for dial-up connections
* Network card - for DSL/Cable internet, and/or connecting to other computers.
* Direct Cable Connection - Use of a null modem, connecting two computers together using their serial ports or a Laplink Cable, connecting two computers together with their parallel ports.