Any area where people live or work needs a supporting
Infrastructure - which entails the technical structures enabling the provision of services; many infrastructure components,
such as power, water, telephone, and sewage lines, are “invisible” to the users, meaning that the user typically do not know where, for example, the water comes from, as long as it flows when they open their faucets.
Just as people/companies rely on basic municipal services to function, businesses rely on an
Information Systems Infrastructure (consisting of hardware, system software, storage, networking, and data centers) to support their decision making, business processes, and competitive strategy.
Application Software helps to
automate business processes, and enables processes that would otherwise not even be possible.
Databases are
collections of related data organised in a way that facilitates data searches. They are vital to an organisation’s operations and often are vital to competitive advantage and success.
Hardware
are computers that run the applications and databases necessary for processing transactions or analysing business data.
The five general classes of computers:
- Supercomputer: most powerful kind of computer (typically not used by business organisations) but used to assist in solving massive scientific problems.
- Mainframe: used primarily as the main, central computing system for major corporations - optimised for high availability, resource utilisation, and security. Used for mission-critical applications, such as transaction processing.
- Servers: any computer or network that makes access to files, printing, communications, and other services available to users of the network. Used to provide services to users within large organisations.
- Workstation: designed for medical, engineering, architectural, or animation and graphics design uses, are optimised for visualisation and rendering of 3D mode,s and have fast processors. large memory, and advanced video cards.
- Personal Computer: used for personal computing and small business computing. Over the past few years, PC’s have increasingly become part of an organisation’s information system infrastructure.
Embedded Systems are optimised to
perform a well-defined set of tasks, ranging from playing MP3 music files to controlling engine performance, traffic lights, or DVD players.
System Software is
the collection of programs that control the basic operations of computer hardware.
The most prominent type of system software is
the Operating System (e.g. OS X, Windows 8) coordinates the interaction between hardware components,
peripherals (e.g. printers), application software (e.g. office programs) and users.
Device Drivers
allow the computer to communicate with various different hardware devices.
Organisations store data for three reasons:
- Operational
- Backup
- Archival
Computer Networking
is the sharing of data or service. The information source produces a message, which is encoded so that it can be transmitted via a communication channel; a receiver then decodes the message so that it can be understood by the destination. Hence, it involves coding, sending, and decoding a message.
Computer networks require:
- A sender and a receiver that have something to share
- A pathway or transmission medium to send the message
- Rules or protocols dictating communication between senders and receivers
Transmission Media
refers to the physical pathway - cables and wireless - used to carry network information.
Protocols define
the procedures that different computers follow when they transmit and receive data. You both might decide the one communication protocol will be that you communicate in English.
Bandwidth
is the transmission capacity of a computer or communications channel, measured in bits per second (bps) or multiples thereof, and represents how much binary data can be reliably transmitted over the medium in one second.
Computer in a network have three roles:
- Servers: any computer on the network that makes access to files, printing, communications, and other services available to the users of the network.
- Clients: any computer, such as a user’s PC or laptop, on the network, or any software application that uses the services provided by the server. A client usually has only one user, whereas many different users share the server. So-called thin clients - microcomputers with minimal memory, storage, and processing capabilities - use desktop virtualisation to provide workers with a virtual desktop environment.
- Peers: any computer that may both request and provide services. The trend in business is to use Client-Server Networks, in which servers and clients have defined roles. With ubiquitous access to local area networks (LANs) and the Internet, almost everyone works in a client-server environment today. Peer-to-Peer Networks enable any computer or device on the network to provide and request servies; these networks can be found in small offices and homes.
Computing networks are commonly classified by size, distance covered, and structure. Common classifications are:
> Personal Area Network (PAN): wireless communication between devices.
Local Area Network (LAN): sharing of data, software applications, or other resources between several users.
Wide Area Network (WAN): connect multiple LANs, distributed ownership and management.
Organisations install Wireless Local Area Networks (WLANs) using
high-frequency radio-wave technology; WLANs are often referred to as Wi-Fi- Networks.
The Internet is a large worldwide collection of
networks that use a common protocol to communicate with each other.
- The World Wide Web is
a software of interlinked documents on the Internet, or a graphical user interface to the Internet that provides users with a simple, consistent, interface to access a wide variety of information. A Web Browser is a software application that can be used to locate and display Web pages, including text, graphics, and multimedia content.
A key feature of the Web is
Hypertext - a document, otherwise known as a Web page, containing not only information but also Hyperlink, which are references or links to other documents.
The standard method of specifying the structure and content of web pages is called
Hypertext Markup Language (HTML).
Web pages are stored on
Web Servers, which process user requests for pages using the Hypertext Transfer Protocol (HTTP).
