Operating Systems

Operating Systems

1. User Interfaces:

   • Types of user interfaces:
     • -Graphical:
       • Graphical user interface (GUI) is: windows, icons and menus which are optimised for mouse and touch gesture input and are visual/interactive.
     • -Command line:
       • Command line: is text based and its less resource heavy but has more commands than a GUI
     • -Menu Language:
       • Menu language is: successive menus presented to the user with a single option on each page. And there are often buttons on a keypad.
     • -Natural Language:
       • Natural language is: an operating system that responds to questions in spoken language e.g Siri or Alexa. It's not always reliable though.

2. Types of operating systems:

   • Windows
   • Mac OS
   • Android
   • Chrome OS
   • iOS

3. Features of Operating Systems

   • Multi-Tasking
     • Multitasking: when there is more than one program running at the same time. For example, word processing a document, whilst doing research, anti-virus, the clock is updating, maintenance task appears. And they are all working at the same time but they have a time slice. And because its so quick, the user doesn't realise.
   • Memory Mangement
     • Memory management: when programs are loading, the operating system decides where they are held in memory. Over time, memory becomes fragmented because programs are loaded and closed because they use different amounts of memory.
   • Device Drivers
     • Device drivers: when an operating system translates operating systems instructions into demands that the hardware will understand. Each peripheral needs a device driver but many are already built into the operating system
   • User management
     • User management: when operating systems provide for different users to log into the computer. The operating system will retain individual settings for each user (icons)
   • File management:
     • file management: when data is stored in files. An extension to the file name tells the operating system which application to load the file into.
   • Overtime:
     • Overtime is when the hard disk becomes fragmented, the operating system may present a logical structure of files into folders and allows the user to rename, delete, move and copy files.
   • Defragmentation:
     • Utilities recognise files on a hard disk to put fragments of files back together and to collect free space. It reduces the movement of a read/write.
   • Data Compression
     • Data compression utilities reduce the size of a file so that it takes up less disk space and is quicker to download over the internet. Compressed files must be extracted before they can be read.
       • Dependant on the algorithm used, data is either lost, reducing the quality of an image/sounds (JPEG) or represented in a different way, using binary retaining the original data in a new compressed format (ZIP)