®Typically an upgrade would be changing from one version to a higher version (e.g. Windows 98 to Windows 2000, or II to Pentium IV). Generally, anything you install in your system that provides an improvement is an upgrade. This is different then a service pack, hot fix, or patch, which are generally provided to correct a specific problem on an existing software package (see Maintenance).
In the world of computers there are three categories of Upgrades. They are: