Utilities - Systems Software

• Utility system software helps to maintain or configure a computer. Many useful utilities are installed with the operating system, but extra utility software can be installed to perform additional tasks
• Defragmentation utilities put broken up files back together
• Files are stored on a hard disk in available spaces. Ideally, entire files would be stored together. However, as files are moved, deleted and change size, lost of small gaps begin to appear on the disk
• When writting files to the disk, the OS splits files into smaller blocks to fill up the gaps
• Over time, the disk becomes more and more fragmented. This makes reading and writing files slower as the read/write head has to move back and forth across the disk
• Defragmentation software reorganises data on the hard drive to put fragmented files back together
• Defragmentation software also moves files to collect all the free space together. This helps to prevent further fragmentation
• As SSDs use flash storage with no moving parts, fragmentation doesn't cause them any problems - they can access data just as quickly however it's arranged
• As SSDs have a limited number of read/writes, defragmenting them can actually shorten their lifespan
• Other utility software includes:

  Disk, registry cleaners, system restore, file managers, anti-virus, anti-spyware, firewalls, automatic updating and system diagnosis tools
• Compression software reduces the size of files by permanently or temporarily removing data from them
• Compressed files take up less disk space and are quicker to download
• Standard file formats for compression include .zip and .rar
• Compressed files need to be extracted before they can be used
• Encryption software scrambles (encrypts) data to stop third parties from accessing it
• The main benefit of encryption is that intercepted or stolen data is still secure, as only the intended readers of the data can unscramble and understand the data
• To decrypt the data, a special 'key' is needed. A computer uses the key and a set of instructions to turn the data back into its original form
• The strong forms of encryption that are used today are very difficult to crack. Hackers can't use brute force attacks to guess the key