Today our life is hard to imagine withoutcomputers. They are found everywhere. The words "bit", "byte", "megabyte" have firmly entered our life. Often ordinary people use them, not knowing what they mean and how they are connected.

## Bits, kilobits ...

Bit is the smallest unit of binaryinformation. More precisely, its quantity. Here we mean information about one of the two states of the object. For example, there is a signal / no signal, true / false, 1/0, etc. The name derives from English abbreviation **would**nary digi**t** ("binary number") = bit.Also, one bit of binary code is called a "bit". In this case, the decimal digit is represented as a zero or one, for example as shown in the table. This is called a "binary number system."

Decimal digit | Binary code | Decimal digit | Binary code |

0 | 0 | 5 | 101 |

1 | 1 | 6 | 110 |

2 | 10 | 7 | 111 |

3 | 11 | 8 | 1000 |

4 | 100 | 9 | 1001 |

As you can see, the numbers 0 and 1 have the same representation, while in the decimal two there are already two digits - 10. And in the eight there are four (1000).

## And what is a kilobit?

The widest application of this number system found in computer technology. In particular, binary numbers are used to number the cells of digital memory.

Let us give an example. The number of all possible addresses on any address bus is equal to the number two to some extent N. Or else - 2^{H}. Here, N denotes the number of bits of the bus. What do we see? The number of cells in the memory chip is equal to one or another degree of number 2. And then - even more interesting. Number 2^{10} = 1024 is very close to 1000. At the same time, a thousand is used as a basis for decimal consoles. Therefore, 1024 bits were called "kilobits". By analogy with *kilo*gram or *kilo*meter. We recall the anecdote given above.

## Bytes and Bits

The following is known from computer science. "Byte" (Eng.byte) is called the storage unit, as well as the processing of digital information. It is the number of bits that are simultaneously processed by the computer. This is a classic.

Modern computer systems use a byte consisting of 8 bits. Therefore, it can accept 256 (2^{8}) of different values.

To convert bytes to megabytes, we proceed simply. Arithmetic for the third class: 1 kilobyte = 1024 bytes. We remember about 2^{10}? A 1 MB = 1024 KB (i.e., 2^{20} = 2^{2x10}) = 1048576 bytes.

## Areas of use

Most often, bytes are used in computer systems, and bits are used in information transmission networks. Typically, to measure speed.

Let us give an example.The Ethernet network provides a data transfer rate in the range from 10 Mbps to 1 Gbps. It should also be clarified that, as a rule, the byte is denoted by the letter "B" (or Latin "B"). "Bit" and recorded. The prefix "kilo" is denoted by the letter "K". It is capital, but not lowercase. A small "k" is written down the name of the decimal attachment "kilo"; 10^{3} = 1000. Now consider in more detail the following question.

## Binary and decimal consoles

How to convert bytes to megabytes, more or lessclear. In early 1999, the well-known IEC (International Electrotechnical Commission) introduced binary consoles to form multiple units of information. The reason for this was the proximity of numbers 1024 and 1000. Similar to the standard decimal consoles used by the international SI system, binary ones differ only by replacing the last syllable by "bi" (from the Latin binarius - binary). It looks like it's shown in the table below.

Console | Abbreviations,adopted by IEC, bytes / bits | The relevantdecimal console | The amount by whichthe initial value amount of information |

kibi | KiB (KiB) / Kibit | kilo (10^{3}) | 1024 or 2^{10} |

meby | MiB (MiB) / Mibit | mega (10^{6}) | 1048576 or 2^{20} |

gibi | GIB (GiB) / Gibit | giga (10^{9}) | 1073741824 or 2^{30} |

teby | TiB (TiB) / Tibit | tera (10^{12}) | 1099511627776 or 2^{40} |

peebee | PiB (PiB) / Pibit | peta (10^{15}) | 1125899906842624 or 2^{50} |

exbi | EiB (EiB) / Eibit | exa (10^{18}) | 1152921504606846976 or 2^{60} |

zebras | ZiB / Zybite | zeta (10^{21}) | 1180591620717411303424 or 2^{70} |

yobi | YiB (YiB) / Yibit | yott (10^{24}) | 1208925819614629174706176 or 2^{80} |

This standard has been approved by many countries, butthe entered names are not used so often, mostly in written speech, and in oral - almost never. As they say, because of cacophony. Maybe you are right. Agree that a kilobit sounds more pleasant than a kibibit, and a megabyte is better than a mebibyte.

Translating bytes into megabytes is clear.But that's not all. There are still two approaches to the formation of multiples of the amount of information. What is even more confusing is the question of how many there are in 1 megabyte byte.

## First approach

In it, the prefixes "kilo", "mega-", etc. are used as binary for the following cases:

In file managers and other softwareProviding with reduced file size. For example, the program reports that the audio recording size is 10 MB. Converting bytes into megabytes in the classical way, we consider the size, which is equal to 10485760 bytes. In the latest development file managers there is a standard indication of the size - using the abbreviated form of binary prefixes, for example MiB (MiB). - Manufacturers of online storage devices, flash cards, video memory.
- The size of the CD-ROM is set only in binary megabytes.

## Second approach

Here prefixes are used as decimal in the following cases:

Hard and optical disks. Their volume is given in decimal megabytes. Exception: CD whose capacity is indicated in binary. - Informal communication.In this case, the values are roughly rounded. For example, a file with a capacity of 10 million bytes can be said to “weigh” 10 megabytes. What do we see here? In this case, the bytes were translated into megabytes is not entirely correct, but when communicating it passes.
- Designation of telecommunication speedscompounds. For example, take the standard 100BASE-TX. In it, 100 Mbps corresponds to a data transfer rate of exactly 100 million bits / s. Let's look at a more “smart” connection with a speed of 10 Gbit / s (standard 10GBASE-X). It corresponds to exactly 10 billion bits / s. That's it. And not a bit more or less.

But with a three-inch floppy 1.44 MB(remember these?) was even more interesting. Their capacity was specified in binary decimal megabytes. It turned out as follows. One such megabyte was equal to 1000 KiB, which is approximately 0.977 MiB, but at the same time 1 KiB was equal to 1024 bytes.

It should be noted that there is a difference betweenthese two options for the presentation of consoles. And if in the case of a kilobyte it does not exceed 2.4%, then for a megabyte it is already 4.9%, for a gigabyte - 7.4%, and for a terabyte - almost 10%. Naturally, not in favor of the binary representation. That is, they "steal" our producers bytes. For example, buy a hard disk with a capacity of 1 TB. As a person who has studied computer science, you are sacredly sure that there are 1099511627776 bytes in it. And it turns out - "only" 1000000000000. That is, you have "bitten off" more than 99.5 billion bytes (almost 98 GB). Is it a lot or a little? Roughly 40 to 200 full-length movies, depending on the format. Doesn't it mean anything? That is, as written above, the tenth part.