Some people take space.
When they enter a room, they make sure everyone knows it.
People who take space have no boundaries and do not respect the boundaries of others.
They are larger than life. Everything about them is loud and over-sized.
People who are taking space are dramatic.
Some people yield space.
When other people walk into a room, they shrink.
People who yield space have but do not protect their boundaries.
They defer to others. Everything about them shifts or is hidden.
People who are yielding space are doormats.
Some people own their space.
When they enter a room, they simply enter and engage.
People who own their space have boundaries and respect the boundaries of others.
They are large, and they exude life. Everything about them is right-sized.
People who are owning space are dynamic.
As much as we may like to believe that people either take, yield, or own space (and that we, of course, own ours), it's an indefensible claim.
We can only hope to be self-aware enough to identify situations in which our lack of confidence manifests as selfish and/or unhealthy self-deprecating behavior and be able to step back into space we rightly own. I know from personal experience and observing others that it's embarrassing and often painful, but it's worth it because balance and authenticity pay dividends in our personal and professional lives.