software

• utility software is software that is used to maintain the computer system for example encryption, compression and defragmentation software
• operating systems provide a platform on whihc users can run programs. provides an interface between the user and the harderware.
• tasks of operating systems - allowing application software to run, memory management, file management
• device drivers translate system instructions into comments that the hardware will understand
• multitasking - runs m ultiple apps by giving each app a time slice of processor time.

  this allows for more than 1 program to be held in memory at a time and allows for data to be shared between them
• scheduling

  new processes eeter and get placed in a ready queue

  these are then run until they are complete or time allotted has expired or they are blocked by a more important task
• ready queue --> process running ---> ready queue, complete or process blocked
• user management allows for multiple users to log onto a single computer by using passwords biometrics
• user management allows for file management as well as access rights fo these files
• file repair attepts to correct issues with the file and restore the file to its original working state
• backup allows for data to be stored safe without the risk of losing it can be automatic on a schedule or manual
• 2 types of back up

  incremental backups or full
• backup can be offsite, in the cloud
• compression reduce the size of a file so it takes up less space - and must be extracted before they can be read
• defragmentation reorganises files on a hard disk, by putting fragments of files together and collecting the free space

  this reduces the movement of the read wrtie head across the surface of the disk
• anti - malware

  keeps your computer and files safe from malware