Bit is the basic unit of measurement of information. In addition to bits, there are many other units of measure. This article will introduce the basic units of measurement in computers.

**1. Bit – BInary digiT (b)**

Bit is the smallest unit of data stored in a computer. All data must be encoded in bits for the computer to understand. A binary digit has 2 states: 0 or 1.

**2. Byte (B)**

A byte consists of 8 bits. Byte (B) usually used to represent the capacity of data storage in the computer.

**3. Conversion table between units of measurement**

In addition to bits and bytes, we have larger units of measurement to meet the growing storage needs.

Unit | Shortened | Capacity (in decimal) | Capacity (in binary) |

Bit | b | 0 hoặc 1 | 0 hoặc 1 |

Byte | B | 8 bit | xxxxxxxx bit |

KiloByte | KB | 10^{3} B | 2^{10} B = 1024 B |

MegaByte | MB | 10^{3} KB | 2^{10} KB |

GigaByte | GB | 10^{3} MB | 2^{10} MB |

TeraByte | TB | 10^{3} GB | 2^{10} GB |

PetaByte | PB | 10^{3} TB | 2^{10} TB |

ExaByte | EB | 10^{3} PB | 2^{10} PB |

ZettaByte | ZB | 10^{3} EB | 2^{10} EB |

YottaByte | YB | 10^{3} ZB | 2^{10} ZB |

**Note**, depending on the definition, we have 1 KiloByte (KB) equal to 1000 Bytes or 1024 Bytes. Hard drive manufacturers often use of decimal in measuring the capacity (1 KiloByte (KB) equals 1000 Byte) to represent the storage capacity of hard drives. This explains, a drive has a capacity of 500 GB but the actual amount of storage is always less than 500 GB.

**3. Hertz (Hz)**

Hertz (Hz) is a unit used to measure the processing speed of the CPU in a computer. The larger this value is, the higher the computer’s processing speed. Processing speed of CPU is usually measured in Megahertz (MHz), Gigahertz (GHz).

Unit | Shortened | Speed |

Herzt | Hz | 1 Hz |

Kilohertz | KHz | 1000 Hz |

Megahertz | MHz | 10^{6} Hz |

Gigahertz | GHz | 10^{9} Hz |

Terahertz | THz | 10^{12} Hz |

**4. bit per second (bps)**

**bps** is a unit of measurement of data transfer rate (DTR) per second in bits. And Bps (Bytes per second) is a unit of measurement of data transfer rate per second in Byte. The transfer rate can be the transfer rate between CPU and RAM, between computers on the network, etc.

**Note**, the **bit** symbol is **the letter b** (**lowercase b**), the **Byte** symbol is **the letter B** (**uppercase B**).

Name | Symbol | Data transfer rate |

Bit per second | bps | 1 bps |

Byte per second | Bps | 8 bps |

Kilobit per second | Kbps | 1000 bps |

Megabit per second | Mbps | 1000 Kbps |

Gigabit per second | Gbps | 1000 Mbps |

Kilobyte per second | KBps | 8.1000 bps |

Megabyte per second | MBps | 8.1000 KBps |

Gigabyte per second | GBps | 8.1000 MBps |

**1 Byte = 8 bit so 1 Bps = 8 bps**, the same for KBps, MBps,…

**5. Rotation speed of hard disk drive**

With HDD (hard disk drive), the speed of the hard drive featured by RPM (revolutions per minute) which means the number of revolutions per minute. Today, hard disk drives typically have a rotational speed of 5400 RPM or 7200 RPM.