Software and firmware upgrades are often downloaded from the Internet. Often the download is a patch—it does not contain the new version of the software in its entirety, just the changes that need to be made. Software patches usually aim to improve functionality or solve problems with security. Rushed patches have been known to cause more harm then good and are therefore sometimes regarded with scepticism for a short time after release (see "Risks"). Patches are generally free.
A software or firmware upgrade can be major or minor and the release version is increased accordingly. A major upgrade will change the version number, whereas the minor will usually follow with a ".01", ".02", ".03", etc. For example, version 10.03 means that that is the third minor upgrade of version 10. The minor upgrades (or updates) are generally free, but the major versions must be purchased. See also: sidegrade.
When you make an upgrade of the same product from one company to the other, you are making a competitive upgrade.
When hardware is upgraded, there is a risk that it will not be compatible with other pieces of hardware in the system. For example, an upgrade of RAM may not be compatible with existing RAM in the computer. Other hardware components may not be compatible after either an upgrade or downgrade, due to the non-availability of compatible drivers for the hardware with a specific operating system. Conversely, there is the same risk of non-compatibility when software is upgraded or downgraded for previously functioning hardware to no longer function.
When software is upgraded, there is a chance that the new version (or patch) will contain a bug, causing the program to malfunction in some way or not function at all. For example, in October of 2005, a glitch in a software upgrade caused trading on the Tokyo Stock Exchange to be shut down for most of the day. Other similar gaffes can be observed from important government systems to freeware on the internet.
Upgrades can also worsen a product subjectively. A user may prefer an older version even if a newer version is perfectly functioning.
The noun 'upgrade' is used in audiophile circles to describe the replacement of a system component or components, for example a low quality or low powered electronic amplifier, with a better quality or more powerful amplifier from the same or different manufacturer's product range ostensibly to improve on the quality of reproduced music from the hi-fi system.
However, the description generally excludes the modification to the sound using different types of interconnect cables, or the replacement of electronic components within the system components by the owners in order to customise the sound, as this would constitute DIY or tweaking.
The word has spawned the noun upgraditis, which is used to describe a person's obsession, compulsion, or addiction akin to a disease to perpetually changing his/her hi-fi system components in order to obtain ever greater enjoyment and fulfilment through enhancements to sound quality. Although the original aim is to improve the sound quality, persons with extreme manifestations of this disorder may completely lose sight of the objective, and would make frequently and highly expensive component changes for its own sake.