Computer Networks
Computer networks have become ordinary notions in today’s highly technological environment, Internet being the best known. In our organization, all computers are connected into a Local Area Network (LAN) based on 100Mb/s Ethernet technology. For a small company, LAN is the best option because it is relatively cheap and data transfer rates are high. 
In my particular department, there is a small part of the entire Intranet. I connect my laptop to a PC of my partner via direct Ethernet cable. Since the PC is connected through second network adapter to other computers in the LAN, I have access to the PC and the entire Intranet of the organization. 
LAN is best for small geographic ranges, and combinations of computers located in one building, however it is inappropriate for connection across separate buildings. If two buildings on opposite sides of the highway have to be connected, the best way to establish this connection would be install little private Metropolitan Area Network or MAN. MAN’s based on Metro-Ethernet are usually best options for interconnecting two or more LAN’s. With the speed of approximately 100Mb/s, a MAN would exchange data through Distributed Queue Dual Bus (DQDB) standard by sending radio signals from antennas on the roofs. However, if there is not enough money for such a connection, a cheaper option might be to simply stretch a LAN wire and integrate the two LAN’s into one big Intranet. 
When connecting multiple computers in a network, a certain pattern should be constructed based on several factors such as the quantity of nodes, the main functions of the network, the physical locations, funding, etc. The most simple – linear topology – is bet for small numbers of computers (2 or 3). Connecting 4 and more computers into a line means spending extra money for additional transmitters, since each computer on such a network (expect the ones at ends) requires a separate connection with the two neighboring computers. Connecting the two nodes at the ends might save time and money, because two times fewer transmitters are required; the data would only go one way and travel through the network until it reaches the destination computer. However, when a single link between any two nodes is cut, the entire network goes down. 
Star topology’s advantage is that it is much safer. The central node, the server or the hub, is the only means for transmission of data. Once the data is sent, it first goes to the server and then to the destination node. Thus, if a separate node is cut off, the network is not substantially affected, however if the server fails, the entire network would go down. This is the same for the tree model as well, only in this case only a section of a network is isolated. 
Mesh and complete topologies are somewhat difficult to design and they are expensive, but they provide better connections and extremely high reliability, especially the complete topology. Generally, business organizations do not need that much reliability; complete patterns are more often used in space and military networks. In real life though, hybrids are most frequently met topologies. 
In business designs automation, notions of front-end and back-end mean the two ends of an automation cycle. Front-end may be a logical design of this cycle, while back-end may be physical verification or “place and route.”