What is a hotel room "upgrade"?

What is a hotel room "upgrade"?

Catharine Hamm (Travel Editor, LA Times) gives expert video advice on: How should I pick a hotel?; What are the most common types of rooms offered by hotels? and more...

A hotel room upgrade means that you start out in one category of hotel room, for example a standard double, and then you are in the next category, which may in California for example, be a partial ocean view. An upgrade from there may be a full ocean view. Or, a hotel room upgrade may simply refer to a more luxurious accommodation.