We advise you to install from scratch to eliminate any remaining uninstalled applications, errors or anything that may harm the experience with the new version of the system, but go ahead that is not mandatory, we can update and go. The truth is that this type of important updates is advisable to do them from scratch even though it is not an essential requirement, that is, If you don't want to install macOS Sierra from scratch, simply download it from the Mac App Store and click on install. Another important data in both cases, whether we update or install from scratch, it is mandatory to make a backup copy of our Mac in Time Machine or similar, so we will avoid headaches if something goes wrong.
In both cases the user chooses the best option and obviously everything will depend on what we do on a daily basis with our team, if we accumulate many applications or documents and others. Do you want to install macOS High Sierra from scratch? We are facing the new Apple operating system for Macs and once we have it downloaded on our computer, two types of installations can be carried out: the one we call Update and the one we call clean or from scratch.
