1. PS/2 mouse port (green). This port is for a PS/2 mouse.
2. PS/2 keyboard port (purple). This port is for a PS/2 keyboard.
3. S/PDIF Outport: It stands for Sony/Phillips Digital Interface, and is an interface to transmit digital audio.
4. HDMI connector: Stands for "High-Definition Multimedia Interface." HDMI is a digital interface for transmitting audio and video data in a single cable. It is supported by most HDTVs and related components, such as DVD and Blu-ray players, cable boxes, and video game systems.
5. DVI (Digital Visual Interface) connector: It is used to send digital information from a computer to a digital display, such as a flat-panel LCD monitor.
6. VGA connector (Video Graphics Array) :VGA cables carry an analog signal as opposed to a digital signal (ones and zeroes). Using higher frequencies, it’s possible to reach a relatively high range of video resolutions. However, video quality directly responds to cable quality, and doubly so on higher resolutions. Due to this, the quality of a VGA image can variate notable across different makes of cables.
7.Firewire header (IEEE 1394): A serial bus used to exchange digital and audio data with high performance abilities.
8. eSATA (External Serial Advanced Technology Attachment): It is an external interface for SATA technologies. It competes with FireWire 400 and universal serial bus (USB) 2.0 to provide fast data transfer speeds for external storage devices.
9. USB (Universal Serial Bus) Port: There are usually a couple of these ports located on each motherboard used for connecting pen drives and external hard drives, like Ipods or Mp3 players.
10. RJ-45 (Registered Jack 45): It is commonly used for an Ethernet or serial connection with an 8 position 8 conductor (8P8C) jack.
11. Audio ports:
a. Line In port (light blue). This port connects a tape, CD, DVD player or other audio sources.
b. Line Out port (lime). This port connects a headphone or a speaker. In 4-channel, 6-channel, and 8-channel mode, the function of this port becomes Front Speaker Out.
c. Microphone port (pink). This port connects a microphone.
d. Side Speaker Out port (gray). This port connects to the side speakers in an 8-channel audio configuration.
e. Rear Speaker Out port (black). This port connects to the rear speakers on a 4-channel, 6-channel, or 8-channel audio configuration.
f. Center/Subwoofer port (yellow orange). This port connects the center/subwoofer speakers.
12. PCI Express x16 graphics interface offers increased bandwidth and scalability over the previous AGP8X generation. PCI Express x16 allows up to 4 GB/s of peak bandwidth per direction, and up to 8 GB/s concurrent bandwidth.
13. PCI Express x4 graphics interface allows up to 800 MB/s of peak bandwidth per direction.
14. PCI (Peripheral Component Interconnect) Slot: Supports peripherals like sound cards, DVD decoders, and graphic accelerators with 32 bits at 33Mhz capabilities. There are usually anywhere from 1 to 6 PCI slots available on the motherboard.
15. Printer Header: It is parallel port used to connect scanners and printers.
16. COM (Communication) Port: The port designed to connect your mouse and modem.
17. IDE Connector: Responsible for connecting the IDE cord used for hard disks, CD drives, and DVD drives.
18. CPU slot: To install the CPU, just slide it straight down into the slot. Special notches in the slot make it impossible to install them incorrectly. So remember if it does not go easily, it is probably not correct. Be sure to plug in the CPU fan's power.
19. SATA Controller: Motherboard will typically have SATA controller for connecting SATA enabled devices such as Hard disks.
20. Power supply plug in: The Power supply, as its name implies, provides the necessary electrical power to make the pc operate. the power supply takes standard 110-V AC power and converts into +/-12-Volt, +/-5-Volt, and 3.3-Volt DC power. The power supply connector has 20-pins, and the connector can go in only one direction.