I already mentioned in one post how freaking big is the place where we life (the Universe). And in the end of the post I mentioned something about observable Universe. So well what is that?
So observable universe is a sphere and its center is Earth, or rather your head so you are in your own observable universe.
This is area that is possible to observe right now since the places outside of this sphere are too far away, their light did not have time yet to reach us.
The diameter of such sphere is 93 giga light years. The reason for this is that as the light left some place and traveled towards you the space expanded making the path longer and thanks to this we are able to see much farther away.
There is another thing called Hubble sphere. It is the area beyond which we will never be able to observe because the stuff there is traveling faster than the speed of light, or rather to make it accurate.. the space between you and outside of Hubble sphere is expanding so fast the light can not get through it.
Actually it can since your Hubble sphere is expanding too and the stuff from first 5 billions years is seen due to this expansion of Hubble sphere.
Actually Hubble sphere is smaller then observable Universe.
Confusing? Watch this video.