Since you make your
/home on other partition that the
/ partition then you ARE NOT going to lost the data unless you will format the /home which you are not going to do.
Just when you format your PC just format the
/ partition and don't touch the
/home partition then you'll be safe.
Ubuntu Community says:
Setting up /home on a separate partition is beneficial because your settings, files, and desktop will be maintained if you upgrade, (re)install Ubuntu or another distro. This works because /home has a subdirectory for each user's settings and files which contain all the data & settings of that user. Also, fresh installs for linux typically like to wipe whatever partition they are being installed to so either the data & settings need to be backed-up elsewhere or else avoid the fuss each time by having /home on a different partition.
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