A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. Typically, connected devices share the resources of a single processor or server within a small geographic area (for example, within an office building). Usually, the server has applications and data storage that are shared in common by multiple computer users. A local area network may serve as few as two or three users (for example, in a home network) or as many as thousands of users (for example, in an FDDI network
A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines. The latter usage is also sometimes referred to as a campus network.
A wide area network (WAN) is a computer network that covers a broad area (i.e. any network whose communications links cross metropolitan, regional, or national boundaries [1]). Less formally, a WAN is a network that uses routers and public communications links. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs), which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet. A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layerwide area networkOSI reference modelphysical layerdata link layer network layer
Like the familiar Local Area Network (LAN) used to connect computers within an office or building, a Small Area Network (SAN) is used to connect Integrated Circuit (IC) components on a printed circuit board, or within a box or system. Due to its low cost, flexibility, and space saving characteristics, Small Area Networks provide device control, media security, and health monitoring connectivity in electronic products ranging from cell phones, to PCs, to large computer server system. Small Area Networks typically include one or more master devices that communicate with one or more slave devices using a serial (one bit at a time) protocol over a common wire bus that connects all the devices together. A master can get the attention of a slave device by sending the slave address over the common wire bus, or by applying a signal to separate device select lines. There are a wide variety of Small Area Networks in use today. These include Inter-Intergrated Circuit Bus (I2C Bus), System Management Bus (SMBus), Serial Peripheral Interface (SPI), 1-Wire, and more. Each bus type offers characteristics such as cost and flexibility that can make it better suited to specific applications
A data center (sometimes spelled datacenter) is a centralized repository, either physical or virtual, for the storage, management, and dissemination of data and information organized around a particular body of knowledge or pertaining to a particular business. The National Climatic Data Center (NCDC), for example, is a public data center that maintains the world's largest archive of weather information. A private data center may exist within an organization's facilities or may be maintained as a specialized facility. According to Carrie Higbie, of Global Network Applications, every organization has a data center, although it might be referred to as a server room or even a computer closet. In that sense, data center may be synonymous with network operations center (NOC), a restricted access area containing automated systems that constantly monitor server activity, Web traffic, and network performancevirtualNOC