Does the universe have boundaries

Is the universe defined by all the matter in space (everything that sprawled out from the big bang) or is it the infinite expanse of space. Also, if the former, could there by multiple universes in space created by multiple big bangs?

It's generally accepted that the universe is finite but unbounded. Sounds like double-talk I know, but look at it this way. Consider an ant crawling around a huge beach ball and never coming to the end. It would consider the beach ball as infinite. If you now consider the ant as only a two dimensional creature and crawling round a three dimensional beach ball, you could understand why the ant would consider the beach ball to be infinite, the three dimensional picture, that shows how restricted its movement really is, is simply not available to it. Thus with the universe, from our perspective, restricted to our view from within the universe, it appears to be infinite, but this is just an illusion, we are confined to the limits of our universe and cannot escape from it. We are bounded within a finite universe.

Another way to say all this is you can start from anywhere you like, travel away from that point and eventually you’ll simply come back to where you were. You’ll never come against and edge or boundary, you’ll just end up back where you started.

Very unlikely.

The major concensus is that the universe is finite and unbounded, but there is some support of an infinite universe as well, though not as much. We can pretty much rule out finite and bounded, but the explaination is complex, and still has tiny wiggle room to not be 100% dismissal, but most would say with great conviction, that the universe is finite and unbounded.

The universe, by definition, is the single, complete encompassing of all matter, energy, time and space, and the laws of physics that govern how all of the aforementioned behave.

The universe is finite in size but without boundaries.