The core of the synchronization magic we’re about to undertake is a MySQL database. Well, it's possible-it just takes a bit of setup. Wouldn’t it be nice, though, if your bedroom Kodi box knew what you watched in the living room, and vice-versa? Would it be nice if you could stop watching a movie in the living room, and resume watching right where you left off somewhere else in the house? Episodes you watched on one TV won't show as 'watched' on another.
By default, if you have multiple Kodi machines, they won't recognize each other.