7. Information systems, definition and classification

What is information system (IS)? (classical definition)Any telecommunications and/or computer related equipment or interconnected system or subsystems of equipment that is used in the acquisition, storage, manipulation, management, movement, control, display, switching, interchange, transmission, or reception of voice and/or data, and includes software, firmware, and hardware

What is IPO model? I: Input - External material/stimuli that enters the system

P: Processing - Actions taken upon/using input or stored material O: Output - Results of the processing that then exit the system

What is the difference between information systems and computer science disciplines? Programming is only one aspect of computer science. IS involves the study of information – its structure, representation,and utilization.

Basic functions of the information system см. в определении

What is management information system (MIS)? are considered to be information systems which provides information specifically for managing an organization generally at a tactical or middle management level

Information systems support business processes in the enterprise

Putting things in context: information technology the hardware, software, and networks that make Information Systems possible., information system a system that uses information technology to capture, transmit, store, retrieve, manipulate, and display information., business process a related group of steps or activities that use people, information, and other resources, to create value for internal or external customers., firm (or organization) - consists of a large number of interdependent business processes that work together to generate products of services in a business environment. business environment includes the firm and everything else that affects its success, such as competitors, suppliers, customers, regulatory agencies, and demographic, social, and economic conditions.

8 Computer networks

What is a computer network?is a system for communicating between two or more computers and associated devices. It is an interconnection of computers for the purposes of sharing information and resources. Division of computer networks according to size Personal area network (PAN) – personal (eg. Bluetooth),Local area network (LAN) – room or building,Metropolitan area network (MAN) – city, town, Wide area network (WAN)

Components of a simple router, PC, NIC Client-server communication client machine(cl.process)->request->network->reply->server machine(ser.process) Packet switching Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination, Previous circuit-switched networks required assembly of complete point-to-point circuit, Packet switching more efficient use of network’s communications capacity Local Arean Network (LAN) is a network that is used for communicating among computer devices, usually within an office building or home Wide Area Network (WAN) can be public or private - example of a public WAN is Internet, Public WAN utilizes public telephone lines and leased lines Virtual Private Network (VPN) Combines public and private lines, Used to access the private network (LAN) from the Internet, Network topologies bus, ring, star Wireless access to the network – basic standards, 3G Higher transmission speeds suitable for broadband Internet access and 4G networks LTE – only packet switched, faster download and upload of multimedia on mobile devices