What is megabyte?

Answer #1

Hi leenajob,

A megabyte is a unit of information or computer storage equal to either exactly one million bytes.

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

* a 1000×1000 pixel bitmap image with 8 bit (1 byte) color depth
* a minute of near CD-quality MP3 compressed music (at 128 kbit/s)
* 5.7 seconds of uncompressed CD audio
* 100 pages of single-spaced 12 point font text in Open Office
* a typical book volume in text format (500 pages × 2000 characters)
* 3 seconds of DVD-quality video

Hope that helps!

Answer #2

To be technical a megabyte is a certain number of bytes. A byte is 8 bits. A bit or BInary digIT) is the smallest discrete unit of information having only two states 0 or 1.

If you talk to a hard drive manufacturer a megabyte is one million, 1,000,000 or 10^6 bytes.

If you talk to a RAM manufacturer or your operating system a megabyte is 1,048,576 or 2^20 bytes.

This disparity has caused countless confusion. Lets say you bring home a new 100 MB hard disk (say this was 20 years ago). Your operating system tells you that your shiny new hard disk is only 95.3 MB.

At the gigabyte level the difference grows. Our hard disk manufacture defines gigabyte as one billion, 1,000,000,000 or 10^9 bytes but our operating system thinks a gigabyte is 1073741824 or 2^30 bytes. A 100 GB disk to the OS is only 93 GB.

In a few years when we start buying terabyte disks the difference between the two measures will grow to 10%. A 1 TB disk will only have 0.9TB if you ask your operating system.

Some people in the industry use MB to indicate 2^20 bytes and mB to indicate 10^6 bytes. For a while this nomenclature seemed to be catching on but today the distinction is largely lost.

Hard drive manufacturers have been sued over the way the define megabyte since it slightly overreports the amount of storage compared to the way everyone else defines it.