Megabyte's an SI-multiple (see prefix mega-) of the unit byte for digital information storage or transmission and's equal to 106 bytes. However, due to historical usage in computer-related fields it's still often used to represent 220 (1024×1024 or ) bytes. In rare cases, it's used to mean 1000×1024 bytes. It's commonly abbreviated as Mbyte or MB (compare Mb, for the megabit). Definition The term "megabyte"'s ambiguous because it's commonly used to mean either 10002 bytes or 10242… (More on Megabytes)