Basically keeping the plant alive after harvest and put it back under 18/6 light schedule to let it grow again (only works with photoperiods, not autos)
Something you can do if it's a strain you love and/or if it's a special pheno with cool traits that you want to keep as a mother plant to take clones from.
Re-veg can take some time though, before you see new shoots coming out and you'd want to put it in a new, bigger pot with fresh medium - and remember that before the plant has started the re-veg process with new shoots and leaves, it's much easier to over fertilize, so keep nutes at a minimum.
All this is just from my experience and my own opinion - I'm not a scientist, haha
![leave-some-buds-and-branches-present-near-the-base__gLivVAwdaiiYvCzf[1].jpg](/data/attachments/4287/4287224-6f7e6d10effe8a838fdf0179dec4d63b.jpg)