System Software

System Software

1. Operating System

   • System Software
     • Systems software is a type of software that controls the computers hardware.
     • It provides an interface between the user of the computer and the hardware.
     • Operating System
       • An Operating System is a type of Systems Software.
   • Application Software

2. Utility Software

   • Encryption software
     • Encryption means to scramble data in a way that it is unreadable to anybody who doesn’t have a key to be able to unscramble this.
     • Data is encrypted using a key and then decrypted using a key
     • Data is encrypted so that it is unreadable if anyone is to intercept it
   • Defragmentation
     • When a hard disk drive is new – files get added onto the disk in order – very much like starting with a blank piece of paper and adding to it
     • As files are deleted this leaves gaps
     • When new files are saved the files fill the gaps and become fragmented
     • Defragmentation software groups fragmented files back together
   • Data Compression
     • Lossy
       • Some of the original data is lost and the original file can not be re-created
     • Lossless
       • The original file can be re-created as no data is lost
   • Backups
     • Full
       • A copy of all data and software on the hard disk drive / server is copied to a backup medium (e.g. an external hard disk drive / DVD-R) and the medium is kept at a different location
       • Take a long time to complete (usually overnight)
       • Recovery takes a long time as it restores all data and programs
     • Incremental
       • A full backup is made initially
       • Each night only the files which have been changed since the last incremental back-up are copied
       • Much faster to complete that full back-ups
       • Takes much longer at restoring than a Full Back up as the full back up would need restoring first and then every incremental back-up since the last full back up
     • Completed to ensure there is a way of restoring files/data/programs in case of computer failure
     • Copies of data and/or software are taken regularly and usually stored in a different location
       • Ensures that if computers are stolen or damaged in for e.g. a fire or a natural disaster that data can be restored and a company do not lose much money