Operating systems

• Software


  The programmes and applications run on a computer system
• Source code


  The software code written by programmers
• Types of operating systems

  • Open
  • Closed
  • Off the shelf
  • Bespoke
  • Shareware
  • Freeware
  • Embedded
• Open source software


  Users can view and modify the code
• Open source software examples 


  • Python
  • Firefox
• Benefits of open source software

  • Unwanted features can be removed to make the software run faster
  • It can be customised to the organisation's needs
  • Users can work together to modify, debug and improve a product
  • Low in price and sometimes free
• Drawbacks of open source software

  • There are security risks - some editors may add malicious code to the program
  • The code may be prone to errors as it may not have been tested fully
  • It may be difficult to receive support
• Off the shelf software

  Made for general use, different people use it for different things
• Off the shelf software examples 


  • Minecraft
  • Adobe Photoshop
• Benefits of off the shelf software

  • It is tested regularly
  • There are regular and secure updates
  • They are created by well known trusted companies
  • It's cheaper than bespoke
• Drawbacks of off the shelf software

  • It may contain unwanted features which slows the programmes down
  • There is a lack of customisable features
  • You may have to pay yearly subscriptions
• Bespoke software


  Custom made for organisations
• Bespoke software examples 


  • In schools or hospitals
• Benefits of bespoke software

  • There are no unwanted features
  • The layout and design can be customised
  • There's a high level of security
  • Lots of software support
• Drawbacks of bespoke software

  • Very expensive
  • Staff may require training to use
  • Programmers must fix all the errors
• Shareware


  Users can trial the programme for a limited amount of time and then they decide if they want to buy it
• Shareware examples 


  • GetRight
  • WinRAR
• Freeware


  Freely available to download and use, but the code is restricted
• Freeware examples 


  • Clash of Clans
  • iTunes
• Embedded systems


  Smaller computer systems installed into a larger one, with a specific purpose
• Embedded systems examples 


  • Washing machine
  • Cars
• Closed source software


  Users cant view or modify the code
• Closed source rights 


  You buy the rights to use not own
• Examples of closed source software

  Fortnite, Spotify and Microsoft
• Benefits of closed source software 


  It’s well tested, updates are regular and secure and they provide support
• Drawbacks of closed source systems

  Relies on company to fix issues and users can’t modify the code