Upgrading software is - as its name already indicates - the opposite of downgrading. -Often, this term is used as a synonym for update, but it is abusive: Upgrade means to update or access a more recent version of a program or software; this implies substantial improvements in its functions. Updates, on the other hand, are standby versions that are usually small and progressive enough to compensate for certain software defects, for example through updates provided in the form of patches (the famous "security updates").
If we take the example of Microsoft software, it means: changing the configuration of the edition of an operating system to provide a more qualitative or more recent version - say, moving from Windows 7 to Windows 10, it's an upgrade, an upgrade, not an update.
Often, modifications, bug fixes, temporary improvements, patches and other software changes are made available in separate updates provided, before being compiled and integrated into a new full version of the software. They can be downloaded and are ready for use. These updates may be free of charge, but this is not always the case. In addition, update data is often insufficient to be used effectively in applications. This is why it is absolutely necessary to make sure, when you buy software licenses in second hand, that they are full licenses, as is the case with Licenceking.fr. There are always suppliers who, under the guise of low prices for second-hand software, sell separate updates of older software that will, in fact, be absolutely unusable.