upgrading

An upgrade is the result of improving something by replacing part of it or adding additional parts. For example, one can upgrade a computer by replacing the CPU with a faster one and by adding more RAM, and afterwards, the computer is an upgrade. Although often used in the context of technology, anything can be upgraded (improved).

Often an update is an upgrade but not always. Update only implies newer (more up-to-date). An update could degrade, or changing to an older version could be an upgrade.