One of the most interesting parts of a science fiction novels that require some sort of transportation from one place to another. This is especially true if you plan on going faster than light. Einstein's theory of relativity states that if a person where to travel at or near the speed of light, they would experience a time shift.

This is classically expressed in the twin paradox. One twin stays on Earth and the other goes in an faster than light vehicle. While the twin in the ship only travels 10 days, more than a year has passed on Earth. So one twin, is almost a year older.

Star Trek created the most well known type of transportation: warp drive. The engine create a warp bubble around the ship that allows it to travel many times the speed of light, but is separate from the time distortion. In essence, the ship isn't is moving, but everything around it is.

The other popular way of traveling far distances is through the use of wormholes. A wormhole is a rip in space-time that connects two unrelated points. Ships either travel through or create wormholes and use them to get from one place to another almost instantaneously. It's like folding a piece of paper in two and connecting two places.

Both concepts are theoretically possible, but the conditions and requirements necessary to create and use them are way outside the current scientific capabilities. It will be hundreds of years before we can do anything even remotely close to FTL travel.