A megabyte (MB) is a unit of digital information storage or transmission, commonly used to measure file sizes and data transfer rates. It is equal to 1,000 kilobytes or 1,000,000 bytes. In contrast, a megabit (Mb) is a unit of data transfer rate equal to 1,000 kilobits or 1,000,000 bits per second. Megahertz (MHz) is a unit of frequency equal to one million cycles per second. Magabyte is not a recognized unit of measurement. Therefore, the correct answer is Megabyte.