Battery

BIOS

CPU (Central Processing Unit)

Brain of the computer

Executes millions of instructions per second

Built using millions of transistors

Needs a heat sink and a cooling method

Memory

Types: Volatile and Non-Volatile

RAM : Random access memory

ROM : Read only memory

BIOS : Basic input/output system

Random Access Memory

Volatile

Accessed Randomly

RAM capacity can be increased

Read Only Memory

Non-Volatile

Mainly used for chipsets

ROM capacity is fixed

Used for its permanence and Security

Data is written once on it during fabrication

Basic input/output system

EEPROM or Flash

Performs POST (Power-on self test)

Contents can be upgraded or re-installed

Motherboard Interfaces

1- AGP (Accelerated Graphics Port)

Used for VGA (Visual Graphics Array) cards

When having built-in VGA, no need for VGA card

Motherboard Interfaces

2- PCI (Peripheral Component Interconnect)

Used for Modems, LAN cards, Sound Cards

Laptops and new PCs have PCI Express

Battery

Lithium Battery

Usually 3 volts

Used to Keep clock and calendar runningWhen the PC is turned off

Power Supply

Used to supply all components ofPC with power

Usually outputs 0, 3.3, 5, 12 volts

Converts AC voltage from outletTo DC voltage for PC components

Storage1- Fixed Storage

Hard Disk- Magnetic disk- High storage capability- Non-volatile- Technologies (IDE,SCSI,ATA,SATA)

Solid State Drive (SSD)- Use transistors- Faster- Non-volatile- No moving parts

Storage2- Removable Storage

Floppy disk-1.44MB- Not used nowadays

Optical Drive- CD- DVD- Blu-Ray

Flash Memory- Removable SSD- High capacities- Cheap and Fast

Computer Ports