Megabyte (MB)

Definition - What does Megabyte (MB) mean?

Megabyte (MB) is a data measurement unit applied to digital computer or media storage. One MB equals one million (106 or 1,000,000) bytes.

The International System of Units (SI) defines the mega prefix as a 106 multiplier or one million (1,000,000) bits. The binary mega prefix is 1,048,576 bits or 1,024 Kb. The SI and binary differential is approximately 4.86 percent.

Techopedia explains Megabyte (MB)

Central processing units (CPU) are built with data control instructions for bits being the smallest data measurement unit. Bit, the smallest data measurement unit, is a magnetized and polarized binary digit that represents stored digital data in random access memory (RAM) or read-only memory (ROM). A bit is measured in seconds and characterized by logical values 0 (on) or 1 (off).

Eight bits equal one byte. Bytes measure device communication speed in thousands of bytes per second.

MB continue to apply to a number of measurement contexts, including:

  • Digitally supported computer and media data: Memory and software according to file format, compression and drive capabilities. MB measures text format, bitmap images, video/media files or compressed/uncompressed audio. For example, 1,024,000 bytes (1,000 × 1,024) often represents the formatted aptitudes of a 3.5-inch hard drive floppy disc with 1.44 MB (1,474,560 bytes).
  • Internet: Files transfer as MBs. For example, a network connection with an eight Mbps DTR must reach a Web DTR of one megabyte (MB) per second (MBps).

In 2000, the Institute of Electrical and Electronics Engineers (IEEE) incorporated the International Electrotechnical Commission (IEC) formal approval of SI metric prefixes (for example, MB as one million bytes and KB as one thousand bytes). Newly added metric terms include:

  • Kibibyte (KiB) equals 1,024 bytes.
  • Mebibyte (MiB) equals 1,048,576 bytes.
  • Gibibyte (GiB) equals 1,073,741,824 bytes.

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