Is 1 mega equal to 1 million?

Excuse me, could you clarify for me if the term "1 mega" is indeed equivalent to "1 million" in terms of numerical value? I've heard the prefix "mega" used in various contexts, and I'm unsure if it consistently denotes a million units across all fields. Is this a standard unit of measurement or does its meaning vary depending on the context? Could you elaborate on when and how "1 mega" is used to signify "1 million"?