~Tilt-Shift Photography~

"Tilt-shift photography" refers to the use of camera movements on small- and medium-format cameras, and sometimes specifically refers to the use of tilt for selective focus, often for simulating a miniature scene.

That's the meaning i quote from Wikipedia(best source for something you don't know)
Using the tilt-shift technique, we can produce two nice effects!

It's selective focus and miniature faking.

In short, selective focus is to direct someone's attention

to a specific part of your picture.

The train will look sharper when the surrounding is blurred.

For miniature faking is to create a small image from a very large picture.

Everything seem so fake in this picture as if the cars are made out plastic..

Here's a nice video made out of tilt-shift technique with time lapse.