Computing

Computing

1. Databases

   • Enables the effective storage of data in a structured and logical way
   • Can be computerised od paper-based
   • used to describle any collection of data
   • large collection of data items and links between them which are structured in a way that allows it to be accessed by a number of different applications

2. HTML

   • Hyper Text Markup Language
   • File containing text that uses tags to say how it should be displayed
   • Includes the location of the URL of other elements like images, sounds and videos to be included as well as hyperlinks to other web pages.
   • Made out of up of a series of tags that tell the web browser how to display the text and image on a web page

3. Networks

   • LAN
     • Local Area Network
       • Network of computers connected in a limited area
       • usually the same building or nearby buildings
       • High speed
   • WAN
     • Wide Area Network
     • Joins computers together over a long distance
     • Can be joined using oublic telephones, fibre optic cables, or satellites etc
     • Built for a particular company but they are private
   • Bus
     • Set of wires which transfer data or power between components inside the computer
     • A bus cannot connect peripherals together
     • BUS CLOCK: while the CPU is busy cycling throughits, program, data is being moved around the computer by means of data buses
       • Each of these buses are also running with their own clocks, each time the clock 'pulses' a data transfer can take place.
   • Star Network
     • Type of network arrangement where each computed is linked to a central server on a dedicated line
     • Arrangement looks like a star with one server in the middle and all the computers surrounding it with one connection
     • Advantage: each lunk to the server is independent of the other computers so the comouter do not have to share bandwidth with eachother
     • Disadvantage: more cabell]ng is needed + if the central server is borken the whole system is broken
   • Ring Network
     • Where one computer is linked to the next and the last computer is linked to the firstn forming a ring shaped network
     • Simple to set up
     • useful for small office networks
     • if one of the links is broken then one side of the cmputers break can't communiate with the other side

4. Types of software

   • Custom Written software: created specifically for the user, it is expensive ( as you have to pay someone to make it) but is often used when the application is very specific or unique so no alternative software is availiable
   • Off the shelf software: suitable for a wide range of users (like a work processor) it is cheaper than Bespoke software and availiable instantly but will come with lots of functionality you dont need and not everything you like
   • Open source software: has a source code open to the public, so anyone can add new features to improve the existing code. It is usually free and created by a huge community of programmers who can distribute their own version of the program.
   • Proprietary Software: created by companies and sold for profit, users cant get access to the source code and must wait for the company tofix any bugs.