Utility Software is essentially what takes care of your computer system. Utility Software consists of but is not limited to the following: Disk cleaner - Finds files that are not in use anymore, or may have never been in use that take up a lot of space on the hard drive. Defragmenter - Locating the files that may be broken and therefore not completely functionary to the system and grouping them together, placing them in a different area of your computer’s hard drive. Checker - Similar to cleaners, disk checkers scan your computer to see if you have any files that are corrupt or unusable due to incorrect saving, to create a more capable computer system. Anti-virus system - A utility that scans your computer for threats or viruses that have made their way on to your computer, whether it’s from visiting un-trusted websites or downloads. It quarantines any viruses and allows you to delete them how you wish. Space analyser - This option shows you how much of your hard drive is being used and by what. It gives you the size of each document, folder, and systems and groups it all together to also show you how much space is not being used. Backups �" Backing up a system is handy to do and very recommended for important files. It saves or copies on your computer system and can restore all or portions of a document or system in the case of a system error, or improper saving of a document. Networks - This utility will check your computer's connectivity to one or more networks. It offers ways of repairing lost connections as well as keeps a record of networks you may have used. All of these put together are used to optimise your computer and make it work in the most efficient way possible.
Utility is another word for tools. They perform the same function on a computer as spanners and screwdrivers do on mechanical things.
Most often used are :-
Registry cleaners - remove unwanted/obsolete/virus-installed entries from Windows Registry
Registry tweakers - make fine tuning for Registry entries, beyond what Windows normally allows
Performance Monitors - available for checking, and issuing warnings about, system components, including memory, CPU speed, cooling systems, hard drives, transfer speeds etc.
Utilty software is used to help you keep up with stuff and help you to make better answers. (: