7 Types of Computer Hardware You Should Understand - dummies

7 Types of Computer Hardware You Should Understand

By Faithe Wempen

Your computing experience is made up of interactions with hardware and software. The hardware is all the tangible computer equipment, such as the monitor, central processing unit, keyboard, and mouse. The main body of a computer is the system unit. The system unit’s case houses a number of essential components.

1The central processing unit (CPU) is responsible for processing most of the computer’s data, turning input into output.

As you might imagine, the speed and performance of the CPU is one of the biggest factors that determines how well a computer works. A CPU is a very small, thin silicon wafer that is encased in a ceramic chip and then mounted on a circuit board.

CPU speed is measured in gigahertz (GHz). The higher this measurement, the faster the CPU can operate. A hertz is a cycle per second; a gigahertz is 1 billion cycles per second. CPU speed is not the only measurement of its performance, though; different CPUs have efficiency-boosting technologies built into them that can increase data throughput in a number of ways.

A fairer comparison between two different CPUs is the number of instructions per second they can perform.

2Memory consists of computer chips that hold data.

One type of memory, called Random Access Memory (RAM), forms the central pool of memory that a computer uses to operate. The more RAM a computer has, the more applications it can have open at once without the computer’s performance starting to bog down. More RAM can also make some applications perform better in general.

Memory capacity is measured in gigabytes (GB), which is a billion bytes. Most basic computers have at least 4GB today, with higher end systems having 16GB or more. Like the CPU, memory consists of small, thin silicon wafers, encased in ceramic chips and mounted on circuit boards. The circuit boards holding memory are called DIMMs, which stands for dual inline memory module.

3A hard drive stores software.

When the computer is turned off, whatever is on the hard drive remains there, so you don’t have to reload software every time you turn on the computer. The operating system and your applications load from the hard drive into memory, where they run.

Hard-drive capacity is also measured in gigabytes (GB), like memory. A typical hard drive might be 500 GB or even 1 terabyte (1,000 GB) or more. Most hard drives sold today are the traditional mechanical type that use metal platters to store data with magnetic polarity, but a newer type, called a solid state hard drive (SSHD), uses a type of memory, resulting in a fast, quiet, and reliable (but expensive) storage alternative.

4In addition to the components in the system unit, a computer may come with one or more input devices.

Input devices include keyboards, mice, trackballs, and touchpads.

5Each computer has some type of display screen.

Depending on the type of computer, the display screen may be built-in, or may be a separate unit called a monitor with its own power cord, as shown. Some displays are touchscreen, so you can use your finger on the screen to provide input to the computer.

Display quality is measured in resolution — that is, the number of pixels (individual colored dots) that comprise the display at its highest resolution. A typical resolution for a notebook PC is 1920 x 1080, for example. The first number is the horizontal resolution and the second one is the vertical resolution.

The aspect ratio of a display is the ratio of its width to its height, expressed in pixels. Displays may either be standard aspect ratio (4:3) or widescreen (16:9). For example, a small device might have a maximum resolution of 800 x 600; if you simplify that to a fraction, it comes out to 4/3.

6Most desktop and notebook computers come with an optical drive, which is a drive that will read CDs, DVDs, and/or Blu-ray discs.

Optical drives get their name from the way data is written and read on the disc. A laser light shines on the surface, and a sensor measures how much light is bounced back from a certain spot.

Some laptop computers come without DVD capabilities because you can download and install software or play videos and music from the cloud (that is, via the Internet), so it’s possible to get along just fine without the ability to play DVDs. However, most desktop computers still come with a DVD drive.

7Whatever computer you have, you will probably want to use it to connect to the Internet. That means you will want it to have a network adapter in it.

That capability may be built into the computer, or it may be added to the computer via an expansion board or a device that plugs into a port.

Internet connectivity can be either wired or wireless. A wired connection requires you to connect a cable from the computer to the device that supplies your Internet connection (such as a cable modem). That type of cable and connection is known as Ethernet.

A wireless connection allows the computer to communicate with the Internet connection device through radio waves. The type of wireless connection used for Internet connectivity is called Wi-Fi, or wireless Ethernet.

If high-speed Internet service is not available in your area, you may need to use a dial-up modem to connect using your home telephone line. Dial-up modems are nobody’s first choice — they are old, slow technology and they tie up your phone line.