4b/4i devs, networking

Computing cycle

◾ Input: Components that help humans put data into the computer. Examples include a keyboard, mouse, and touch screen. ◾ Processing: Components that move and process the data inside the computer. The motherboard and its processor and memory chips fall into this category. ◾ Output: Components that provide the results of the processing to humans. The monitor is the primary output device; other examples include printers and speakers. ◾ Storage: Components that store software and data until it is needed. Storage components include hard drives, USB flash drives, and DVDs.

Input Devices An input device provides a way to get data into the computer. The oldest and most common input device is a keyboard. A desktop PC has an external keyboard, while a notebook PC has a built-in keyboard. Tablets and smartphones have a software-based keyboard that pops up onscreen when needed.
Computers that use a graphical interface usually employ a pointing device. The pointing device moves an onscreen pointer (usually an arrow) to align with objects onscreen, and then the user presses a button on the pointing device to do something to the pointed-at object. A mouse is the most common pointing device, but there are many other types too, such as trackballs, touchpads, and touch-sensitive screens. You will learn more about input devices in Chapter 3, “Input, Output, and Storage.”

Processing Devices The motherboard is the large circuit board inside the computer that everything else plugs into. The key components located on the motherboard are the processor (also called the Central Processing Unit, or CPU) and the memory (also called Random Access Memory, or RAM). To support these components, the motherboard has electrically conductive pathways called buses that carry the data from place to place, and a chipset, which is a controller that directs the bus traffic. Figure 1.13 shows a motherboard removed from the computer case so you can see it more clearly.

Output Devices Information comes out of a computer through an output device such as a monitor. When you move the mouse or type a character on a keyboard, you see the results instantly on the monitor. The monitor helps you communicate with the operating system; without the monitor, you wouldn’t know if the OS had received and understood your instructions or if the application had accepted the data you input. Besides monitors, other output devices include printers (for producing hard-copy output) and speakers (for providing audio feedback).
Storage Devices Storage devices enable software and data to be preserved and reused. Storage can be either removable or non-removable. (Non-removable storage is actually removable too if you have the right tools and knowledge, but in this case the distinction refers to being easily removable or not.)
The most common type of storage is an internal hard drive, which is a sealed metal box inside the system unit. Hard drives are usually internal, making them non-removable. Some hard drives are removable, though; external hard drives easily connect to and disconnect from a port on the outside of the system unit. Other removable storage devices include USB flash drives and optical discs (CDs and DVDs).

Ethernet Networking Most computers today are part of one or more networks. A network is a group of computers that share resources (such as printers or Internet service) and/or data (such as files). The most common network standard is Ethernet. Ethernet networks can be either wired or wireless (or a combination of the two), but the term Ethernet is most often applied to the wired kind of connection. Figure 1.14 shows an Ethernet port on the side of a notebook PC. Most PCs have a network adapter, which provides network connectivity services and a port into which you can plug an Ethernet cable.

Bluetooth Networking Bluetooth is a short-range wireless alternative to wireless Ethernet  (Wi-Fi), used primarily to connect wireless devices directly to specific computers. For example, you might have a Bluetooth wireless headset for your cell phone, or a Bluetooth speaker for your MP3 player. Bluetooth’s limited range (10 meters) makes it impractical as a replacement for Wi-Fi, but it provides an easy and economical way for one device to connect with another within a limited space without Ethernet hardware.
The Internet The Internet is the world’s largest network. When you use the Internet, your computer becomes a member of this giant network, and you can communicate with any other computer on the Internet, to the extent that its owner has chosen to make it available. For example, you can exchange email messages, download files, and view web pages stored anywhere in the world.
Individual computers don’t connect directly to the Internet, however; they go through an Internet service provider (ISP), a company that provides a connection to the Internet for a fee. Your ISP may be your local phone or cable TV company, or at work or school it may be a service that your employer or school partners with. An ISP provides a device (a modem or terminal adapter) that translates your computer’s requests into Internet-compatible data.