Q. Why is a cemetery called Bet Olam (“Place of Eternity)?
A. The term derives from the end of Kohelet chapter 12 (verse 5), which speaks of a person who dies going to their “long (i.e. eternal) home”.
This is only one of the terms for a cemetery.
Another is Bet Chayyim (“House of Life”) in which the word “life” is a euphemism that really means the opposite, or, which fits in better with Jewish thinking, it is where a body is laid to rest when the soul is now in another dimension of life.
Since we believe that there are two worlds, this world and the World to Come, the person who has died remains alive in some sense.
Another term is Bet K’varot (“Place of Graves”). In England there is a colloquial custom of calling the cemetery “the grounds”, which might have begun as a softer alternative to the blunt word “grave”.
There are a number of colloquial distortions of the Hebrew name for a cemetery, e.g. “Bsaylum”.