Time-travel is like you physically travel the time.
i.e. You now live in 2003 and you want to come back somewhere in past, the short process of you are being transported to the past by this 'thing' is the actual meaning of Time-Travel.
Very few people claimed that they had traveled the time (i.e. coming back to the past, going to the future), but to be honest I must confess I do not believe these people.
Many other people also believe that it is possible to slow down the time. I guess what they really mean by this is that the biological activities within their bodies slow down hence they really look 18 and their body works as it is 18 year-old although it is 40 year-old. So in this case, Time does not slow down, but the activities within your body slow down.
In my opinion, you cannot travel the time physically but maybe you can travel the time with your minds.
There was a great person called Nostradamus lived in France back centuries ago and he could see the future by jusy using his mind. Many people in today's life can also do such thing. This maybe possible.
But with this mind power, you may go to the future or come back to the past as a different person. You will enter someone else's body (can be human beings, animals et cetera).
You cannot bring there your present body, because if you see yourself in the future by your present body, there might be something bad happen to you both and indeed to the environment.
Although I do not acquire great knowledge of Physics and Electronics, I think the Black Hole and/or the Bermuda Triangle have something to do with time travel.