Bits and Bytes

Have you ever found yourself going through computer specs or advertisements scratching your head over all the different terms used for storage and memory? For example, individual files are listed in megabytes, memory in gigabytes, and storage in gigabytes or terabytes. This article will give some history of the terms and also explain the differences between them.

To explain, remember that the decimal system is based on a 10-digit system of numbers between 0 and 9. All numbers can be expressed using this system. Conversely, in relation to technology, computers communicate based on the two-digit binary system. According to www.websters.com, binary is defined as “Anything composed of two parts. In modern computers, information is stored in banks of components that act like switches. Since switches can be either on or off, they have a binary character, and we say that the computer uses “binary arithmetic” to do its work.”

Here, the binary system only has two digits, either 0 or 1 (on or off / yes or no). Bit is derived from the words Binary digIT. Specifically, each 0 or 1 in binary equals one bit. Comparatively, a byte is normally made up of 8 individual bits. Why 8 bits? The same question could be asked why eggs come in a carton of 12, hot dogs in a pack of 10, and hot dog buns come in a pack of 8. Actually, 8 bits came about because early computers could only send 8 bits at a time. According to Wikipedia.org, “Historically, byte size was determined by the number of bits required to represent a single character from a Western character set.”

To compare both the decimal and binary systems side by side, look at the chart below displaying the numbers 0 to 10:

Decimal Binary 0 00000000 1 00000001 2 00000010 3 00000011 4 00000100 5 00000101 6 00000110 7 00000111 8 00001000 9 00001001 10 00001010

If it sounds confusing, don’t feel alone. Computer manufacturers add to this confusion by sometimes using the decimal system while at other times using the binary system. For example, hard drives or USB flash drives are normally labeled in the 10-digit decimal system, while memory (RAM) is labeled using the 8 bits = 1 byte binary system.

Therefore, the bottom line is that bits (in binary) are based on powers of 2, while bytes (in decimal) are based on powers of 10. Since computers store such large amounts of data, other names come into play when describing memory and storage, especially with today’s ever increasing capacities. For instance, terms such as megabyte, gigabyte, and terabyte are now commonly used.

With all the terms currently being used, a common question is…..which is larger, a megabyte, a gigabyte, or a terabyte? The three most common terms used today are mega, giga, and terabyte. Of those, terabyte is largest. Just remember that every step up to the next level is 1,000 times larger than the previous level. With that, a gigabyte is 1,000 times larger than a megabyte and a terabyte is again 1,000 times larger than a gigabyte. The chart I produced below demonstrates this:

I could go on and on about the differences in bits, bytes, binary and decimal. However, here are some data sizes in more practical terms. For example, an mp3 music file is about 3,500 bytes, or 3.5MB (megabytes). An average digital photo ranges from 3,000 to 5,000 bytes or 3 to 5MB, depending on the photo quality and megapixels of the camera.  Speaking of megapixels, mega denotes a camera is x number of millions of pixels.

The chart below shows more practical applications of data size. It can also be viewed at www.searchstorage.com:

Information object How many bytes A single text character 1 byte A typical text word 10 bytes A typewritten page 2 kilobytes ( KB ) A short novel 1 megabyte ( MB ) A high-resolution photograph 3 megabytes The contents of a CD-ROM 500 megabytes A pickup truck filled with books 1 gigabyte ( GB ) The contents of a DVD 4-7 gigabytes A library floor of academic journals 100 gigabytes 50,000 trees made into paper and printed 1 terabyte ( TB ) An academic research library 2 terabytes The print collections of the U.S. Library of Congress 10 terabytes The National Climactic Data Center database 400 terabytes All U.S. academic research libraries 2 petabytes ( PB ) All printed material in the world 200 petabytes

If you would like to view other types of data ‘facts’ in real world terms, please visit www.wikipedia.org. To demonstrate how vast some of the data are; I’ve pasted more storage facts below:

LaCie released the world’s first 1 TB external hard drive in early 2004. Hitachi introduced the world’s first one terabyte internal hard drive in 2007. Ancestry.com claims approximately 600 terabytes of genealogical data with the inclusion of US Census data from 1790 to 1930. Facebook has just over 1 petabyte of users’ photos stored, translating into roughly 10 billion photos. Google processes about 20 petabytes of data per day.

With ever increasing volumes of data, the terms used for memory and storage will keep changing. Soon, the most common terms will move from giga and terabyte to peta and exabyte. If anyone would like more information, please feel free to contact me at kparrett@hotmail.com.