BLUETOOTH

Bluetooth is an open wireless protocol for exchanging data over short distances (using short length radio waves) from fixed,PC and mobile devices, creating personal area networks(PANs). It was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization.

USB EXTENSION CABLE

Do you need to extend the distance from your computer to a USB device such as a printer or scanner? According to the USB specification, you can use passive extension cables (i.e., cables without an active repeater chip in them) for distances up to 16 feet. Beyond sixteen feet, you need a cable that will boost the signal in order to avoid losing data or, worse yet, damaging USB equipment.

The maximum distance that you can reach by chaining Active USB Extension Cables together is 80 feet. By using 16 foot cables (the most common length available) you can safely chain up to 4 of these together without risking data loss or damage to your device (in addition to the 4-active extension cables you will use a regular device cable at the end that can be up to 16 feet - this is how you achieve the maximum distance of 80 feet).
In order to use a USB Extension Cable with a device, you plug the extension cable directly into the USB port on your desktop or notebook. On the other end of the cable, you will have a type A female port where you can plug your device cable in, which will be connected to the device on the other end.

CARD READER

A memory card reader is a device used for communication with a smart card or a flash memory card. A business card reader is a scanning device used to scan and electronically save business cards. Amagnetic card reader is a device used to scan cards containing magnetic data strips. A punched card reader is a device used to read holes in punched cardboard cards.

video card

A video card, video adapter, graphics-accelerator card, display adapter or graphics card is an expansion card whose function is to generate and output images to a display. Many video cards offer added functions, such as accelerated rendering of 3D scenes and 2D graphics, video capture, TV-tuner adapter, MPEG-2 and MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor), while other modern high performance cards are used for more graphically demanding purposes such as PC games.

Video hardware can be integrated on the motherboard, as it often happened with early computers; in this configuration it was sometimes referred to as a video controller or graphics controller.

WEBCAM

A webcam is a video capture device connected to a computer orcomputer network, often using a USB port or, if connected to a network, ethernet or Wi-Fi.

The most popular use is for video telephony, permitting a computer to act as a videophone or video conferencing station. This can be used in messenger programs such as Windows Live Messenger,Skype and Yahoo messenger services. Other popular uses, which include the recording of video files or even still-images, are accessible via numerous software programs, applications and devices.

Webcams are known for low manufacturing costs and flexibility.^[1]

The term "webcam" may also be used in its original sense of a video camera connected to Web continuously for an indefinite time, rather than for a particular session, generally supplying a view for anyone who visits its Web page. Some such webcams, for example those used as online traffic cameras, are expensive, rugged professional-grade hardware.

PRINTER

In computing, a printer is a peripheral which produces a hard copy (permanent readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most newer printers, aUSB cable to a computer which serves as a document source. Some printers, commonly known as networkprinters, have built-in network interfaces (typically wireless and/or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support both local and network connected users at the same time. In addition, a few modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanner and/or fax machine in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called Multifunction printers (MFP), Multi-Function Devices (MFD), or All-In-One (AIO) printers. Most MFPs include printing, scanning, and copying among their features.

A Virtual printer is a piece of computer software whose user interface and API resemble that of a printer driver, but which is not connected with a physical computer printer. Instead of producing a hard copy of documents on paper (or other print mediums), virtual printers are interfaces for creating PDF files of the printed document, or sending faxes over the telephone using a connected modem.

Printers are designed for low-volume, short-turnaround print jobs; requiring virtually no setup time to achieve a hard copy of a given document. However, printers are generally slow devices (30 pages per minute is considered fast; and many inexpensive consumer printers are far slower than that), and the cost per page is actually relatively high. However this is offset by the on-demand convenience and project management costs being more controllable compared to an out-sourced solution. The printing press naturally remains the machine of choice for high-volume, professional publishing. However, as printers have improved in quality and performance, many jobs which used to be done by professional print shops are now done by users on local printers; see desktop publishing. The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.[1]

LAN CARD

A network interface card, network adapter, network interface controller (NIC), or LAN adapter is a computer hardware component designed to allow computers to communicate over a computer network. It is both an OSI layer 1 (physical layer) and layer 2 (data link layer) device, as it provides physical access to a networking medium and provides a low-level addressing system through the use ofMAC addresses. It allows users to connect to each other either by using cables or wirelessly.

Although other network technologies exist, Ethernet has achieved near-ubiquity since the mid-1990s. Every Ethernet network card has a unique 48-bit serial number called aMAC address, which is stored in ROM carried on the card. Every computer on an Ethernet network must have a card with a unique MAC address. Normally it is safe to assume that no two network cards will share the same address, because card vendors purchase blocks of addresses from the Institute of Electrical and Electronics Engineers (IEEE)and assign a unique address to each card at the time of manufacture.

Whereas network cards used to be expansion cards that plug into a computer bus, the low cost and ubiquity of the Ethernet standard means that most newer computers have a network interface built into the motherboard. These either have Ethernet capabilities integrated into the motherboard chipset or implemented via a low cost dedicated Ethernet chip, connected through the PCI (or the newer PCI express) bus. A separate network card is not required unless multiple interfaces are needed or some other type of network is used. Newer motherboards may even have dual network (Ethernet) interfaces built-in.

The card implements the electronic circuitry required to communicate using a specific physical layer and data link layer standard such as Ethernet or token ring. This provides a base for a full network protocol stack, allowing communication among small groups of computers on the same LAN and large-scale network communications through routable protocols, such as IP.

There are four techniques used to transfer data, the NIC may use one or more of these techniques.

• Polling is where the microprocessor examines the status of the peripheral under program control.
• Programmed I/O is where the microprocessor alerts the designated peripheral by applying its address to the system's address bus.
• Interrupt-driven I/O is where the peripheral alerts the microprocessor that it's ready to transfer data.
• DMA is where an intelligent peripheral assumes control of the system bus to access memory directly. This removes load from the CPU but requires a separate processor on the card.

A network card typically has a twisted pair, BNC, or AUI socket where the network cable is connected, and a few LEDs to inform the user of whether the network is active, and whether or not there is data being transmitted on it. Network cards are typically available in 10/100/1000 Mbit/s varieties. This means they can support a notional maximum transfer rate of 10, 100 or 1000 Megabits per second.

A network interface controller (NIC) is a hardware device that handles an interface to a computer network and allows a network-capable device to access that network. The NIC has a ROM chip that contains a unique number, the multiple access control (MAC) Address burned into it. The MAC address identifies the device uniquely on the LAN. The NIC exists on both the 'Physical Layer' (Layer 1) and the 'Data Link Layer' (Layer 2) of the OSI model.

Sometimes the words 'controller' and 'card' are used interchangeably when talking about networkingbecause the most common NIC is the network interface card. Although 'card' is more commonly used, it is less encompassing. The 'controller' may take the form of a network card that is installed inside a computer, or it may refer to an embedded component as part of a computer motherboard, a router,expansion card, printer interface or a USB device.

A MAC address is a 48-bit network hardware identifier that is burned into a ROM chip on the NIC to identify that device on the network. The first 24-bit field is called the Organizationally Unique Identifier (OUI) and is largely manufacturer-specific. Each OUI allows for 16,777,216 Unique NIC Addresses. Smaller manufacturers that do not have a need for over 4096 unique NIC addresses may opt to purchase an Individual Address Block (IAB) instead. An IAB consists of the 24-bit OUI plus a 12-bit extension (taken from the 'potential' NIC portion of the MAC address.)