Networking Relationships What is a computer network?

What is a Computer Network? –a network is: group of two or more nodes connected together by transmission media for the purpose of sharing resources

Network Elements –Node a node is any hardware device that is directly connected to a network Examples include: –Assorted types of computer systems –Printers and plotters –Scanners –Communication hardware (modems, etc.) –Hard Disk Drives

Network Elements –Transmission Media the transmission media consists of the physical connections, that facilitate the transmission of signals, between nodes on a network –Telephone lines –Twisted Pair cable –Coaxial Cable –Fiber-optic Cable –Microwave Transmission –Satellite Transmission

Network Elements –Resource a resource is a hardware, software, or data source Examples include: –Storage space on Secondary Storage –Ability to send a from an iPhone –Processing power of high performance CPU –Outputting to high quality printer –Application executed from HD of remote system –Transfer of data files from node to node –Web Pages requested and received

Types of Nodes –A typical network includes several nodes; some nodes act as server, some as client, and some as both server and client –Server a server is a node that makes its resources available to and for use by other network nodes; therefore, a server shares its resources across the network –Client a client is a node that requests and uses resources on a network which are made available and shared by a server on the network

How are Resources Shared? –Resources are shared across networks through network services –Service a service is a communication scheme or standard supplying some public demand for shared resources on a network; scheme consists of user interaction characteristics and the protocol for transmitting signal.

Network Services –Lets look at a specific network, the Internet –Internet the Internet is a global public network facilitating all sorts of services; the Internet is the largest world-wide network Like in smaller networks, resources are shared over the Internet using services

Network Services –Some of the services facilitated by the Internet are: –the service is a network service that facilitates exchange of messages World Wide Web –the world wide web service (WWW) is a network service facilitating the transfer and display of hypertext document files File Transfer Protocol –the file transfer protocol service (FTP) is a network service that allows for relatively fast transfer of whole files