According to https://en.wikipedia.org/wiki/Closed_manifold "In mathematics, a closed manifold is a manifold without boundary that is compact. In comparison, an open manifold is a manifold without boundary that has only non-compact components."
Closed manifold is a compact manifold without boundary.
Open manifold is a manifold without boundary that has only non-compact components.
Is open manifold opposite or antonym of closed manifold? (It seems not, but why not?)
How do we call "compact manifold with boundary"?
What are the differences between open manifold and non-compact manifold?
How is the concept "open" in open manifold compared with the "open" in open set in set theory with topology, and open cover in topology? These open seem to mean different things.