What is a worm hole??

It's a hypothetical tunnel through space-time that unlike a black hole, has two openings instead of one. Kip Thorne committed a couple chapters to them in his book "Black holes and time warps". Most likely they would collapse instantly if created, so maintaining them would require the existence of something speculatively called "exotic mater". Unlike normal matter, it would have negative mass and therefore negative gravity. This would prevent a singularity from forming and also allow the geometry of space-time to be manipulated based on the arrangement of matter and exotic matter. The amount of energy needed for this, however, would probably exceed anything our sun could produce in its lifetime. Hypothetically, however, you could connect two points in space-time using this, allowing someone to travel through both time and space.

I will take Richard's wild card to get to the concept of worm hole. "roughly the idea is a "tunnel in the fabric of space( what ever that means)" that lets an object pass from one position in space to anther WITHOUT crossing the space in between. just a wild idea."
What does fabric of space mean? Normal events that occur in the Earth/space time that we experience is due to gravitational lines that criss/cross the space in the universe. Thus events happen in precise and predictable periods of time. So, the moon rotates around the earth, once in 28 days, etc.
But, now consider the comet, Swift Tuttle. It consists of a 5 km mass, chiefly made up of ice particles. This takes a course in the solar system such that it will cross the path of the earth in 2115 or 2116. Suppose the movies were true, and we went by a space craft and put a few nuclear bombs on the comet while it is approaching Earth from far away, say near Saturn, then the comet could be blown up and would disappear.
But, we would find the same comet a few moments later, steadily heading towards Earth, and much closer now.