Term of the Moment
Ken Thompson Hack
Definition: LAN
(Local Area Network) A communications network that is confined to a building or complex. A LAN is a local network, whereas a WAN is a wide area network that spans long distances (see WAN). For example, a home network is a LAN; the Internet is a WAN.
The Transport
Data transfer over a LAN is managed by the TCP/IP protocol, and the physical transmission by cable is Ethernet. Mobile devices are connected by Wi-Fi, Ethernet's wireless counterpart. See twisted pair, TCP/IP and Ethernet.
The Wireless Router
A wireless router provides the required LAN hardware. The router creates the Wi-Fi hotspot and generally contains four Ethernet ports for cabling computers, printers and other devices to the LAN (see wireless router).
Clients and Servers
The "clients" in a LAN are the user's computers running Windows, Mac or Linux, while the "servers" are computers that hold programs and data shared by the clients. A printer is a type of server. See server and client/server.
In Companies: Thick and Thin Clients
In a company LAN, the user's computer may have many installed applications. These "thick" clients are the norm and contain full installations of software; however, some organizations use "thin" clients, whereby their PCs function like terminals to a server in the company datacenter or to servers on the Internet (see Remote Desktop Services and cloud computing). See thin client and client/server.
In the Home: Thick Clients
In the home, the user's computer generally has several programs installed along with a Web browser that provides access to websites on the Internet. A major difference between a home LAN and a company LAN is that most homes do not use dedicated servers. See home network.
Clients and Servers in a Company LAN
Software in a Network Client
Software in a Network Server
The Transport
Data transfer over a LAN is managed by the TCP/IP protocol, and the physical transmission by cable is Ethernet. Mobile devices are connected by Wi-Fi, Ethernet's wireless counterpart. See twisted pair, TCP/IP and Ethernet.
The Wireless Router
A wireless router provides the required LAN hardware. The router creates the Wi-Fi hotspot and generally contains four Ethernet ports for cabling computers, printers and other devices to the LAN (see wireless router).
Clients and Servers
The "clients" in a LAN are the user's computers running Windows, Mac or Linux, while the "servers" are computers that hold programs and data shared by the clients. A printer is a type of server. See server and client/server.
In Companies: Thick and Thin Clients
In a company LAN, the user's computer may have many installed applications. These "thick" clients are the norm and contain full installations of software; however, some organizations use "thin" clients, whereby their PCs function like terminals to a server in the company datacenter or to servers on the Internet (see Remote Desktop Services and cloud computing). See thin client and client/server.
In the Home: Thick Clients
In the home, the user's computer generally has several programs installed along with a Web browser that provides access to websites on the Internet. A major difference between a home LAN and a company LAN is that most homes do not use dedicated servers. See home network.
This shows the private employee-facing side and the public-facing site. In large companies, multiple servers are used for each type of service. Today, it is rare to see a remote access server for analog dial-up connections.
These are examples of common applications found in a user's machine. Printers may be connected to clients or servers wired or wireless (see print server).
These are the common services in a network server.