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megabyte

 
Dictionary: meg·a·byte   (mĕg'ə-bīt') pronunciation
 
n. (Abbr. MB)
  1. A unit of computer memory or data storage capacity equal to 1,048,576 (220) bytes.
  2. One million bytes.

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Modern Science: megabyte
 
megabyte (MEG-uh-beyet)

A unit of computer information: one million bytes.

 
Veterinary Dictionary: megabyte
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One million bytes (approximately 1 million characters = 1000 KB).

 
Wikipedia: Megabyte
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Megabyte is an SI-multiple (see prefix mega-) of the unit byte for digital information storage or transmission and is equal to 106 (1000000) bytes. However, due to historical usage in computer-related fields it is still often used to represent 220 (1024×1024 or 1048576) bytes. In rare cases, it is used to mean 1000×1024 (1024000) bytes. It is commonly abbreviated as Mbyte or MB (compare Mb, for the megabit).

Prefixes for bit and byte multiples
Decimal
Value SI
1000 k kilo
10002 M mega
10003 G giga
10004 T tera
10005 P peta
10006 E exa
10007 Z zetta
10008 Y yotta
Binary
Value IEC JEDEC
1024 Ki kibi K kilo
10242 Mi mebi M mega
10243 Gi gibi G giga
10244 Ti tebi
10245 Pi pebi
10246 Ei exbi
10247 Zi zebi
10248 Yi yobi

Contents

Definition

The term "megabyte" is ambiguous because it is commonly used to mean either 10002 bytes or 10242 bytes. The confusion originated as compromise technical jargon for the byte multiples that needed to be expressed by the powers of 2 but lacked a convenient name. As 1024 (210) is roughly equal to 1000 (103), roughly corresponding SI multiples began to be used as approximate binary multiples. By the end of 2007, standards and government authorities including IEC, IEEE, EU, and NIST, had addressed this ambiguity by promulgating standards requiring the use of megabyte to describe strictly 10002 bytes and "mebibyte" to describe 10242 bytes. This is reflected in an increasing number of software projects, but most file managers still show file sizes in "megabytes" ("MB") in the binary sense (10242 bytes). The term remains ambiguous and it can follow any one of the following common definitions:

  1. 1000000 bytes (10002, 106): This is the definition recommended by the International System of Units (SI) and the International Electrotechnical Commission IEC. This definition is used in networking contexts and most storage media, particularly hard drives, Flash-based storage[1], and DVDs, and is also consistent with the other uses of the SI prefix in computing, such as CPU clock speeds or measures of performance.
  2. 1048576 bytes (10242, 220): This definition is most commonly used in reference to computer memory, but most software that display file size or drive capacity, including file managers also use this definition. See Consumer confusion (in the "gigabyte" article).
  3. 1024000 bytes (1000×1024): This is used to describe the formatted capacity of the "1.44 MB" 3.5 inch HD floppy disk, which actually has a capacity of 1474560 bytes.

Megabyte examples

1.44 MB floppy disks can store 1,474,560 bytes of data. MB in this context means 1,000×1,024 bytes.

Depending on compression methods and file format, a megabyte of data can roughly be:

  • a 1024×1024 pixel bitmap image with 256 colors (8 bpp color depth).
  • 1 minute of 128 kbit/s MP3 compressed music.
  • 6 seconds of uncompressed CD audio.
  • a typical book volume in text format (500 pages × 2000 characters per page).

See also

References

  1. ^ SanDisk USB Flash Drive "Note: 1 megabyte (MB) = 1 million bytes; 1 gigabyte (GB) = 1 billion bytes."

External links


 
Translations: Megabyte
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Dansk (Danish)
n. - megabyte (edb)

Nederlands (Dutch)
megabyte (maat voor computergeheugen)

Français (French)
n. - (Comput) mégaoctet

Deutsch (German)
n. - (Comp.) Megabyte

Ελληνική (Greek)
n. - (Η/Υ) εκατομμύριο χαρακτήρων, μεγκαμπάιτ

Italiano (Italian)
megabyte

Português (Portuguese)
n. - megabyte (Comp.)

Русский (Russian)
мегабайт

Español (Spanish)
n. - megabyte, megaocteto

Svenska (Swedish)
n. - megabyte

中文(简体)(Chinese (Simplified))
兆字节

中文(繁體)(Chinese (Traditional))
n. - 百萬位元組

한국어 (Korean)
n. - 메가 바이트

日本語 (Japanese)
n. - メガバイト

العربيه (Arabic)
‏(الاسم) الميغابايت (مليار حرف)‏

עברית (Hebrew)
n. - ‮מגבייט - מיליון בתים (מחשב)‬


 
Best of the Web: megabyte
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Some good "megabyte" pages on the web:


Math
mathworld.wolfram.com
 
 
 

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
Modern Science. The Dictionary of Cultural Literacy, Second Edition, Revised and updated Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 1993 by Houghton Mifflin Company . All rights reserved.  Read more
Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Megabyte" Read more
Translations. Copyright © 2007, WizCom Technologies Ltd. All rights reserved.  Read more

 

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