An inter-dimensional being or extra-dimensional intelligence is a type of entity existing in, or emanating from, a dimension beyond our own. They can step into our dimension through wormholes that exist all around us, they are invisible to the human eye. They occur in nooks and crannies in space and time.
Ghosts and spirits maybe flashes of the past, the future, or even another timeline in another parallel universe. Time slips maybe just that, tiny bits of time sucked away, leaving us with that stutter in our journey. Premonitions maybe our unconscious perception of our future selves or events. Aliens maybe from the other side of the universe, or from a parallel universe. The possibilities are endless.