Gb

Gb is an abbreviation used in several scientific and technical contexts, most commonly to denote either a gigabit or a gigabase, depending on the field.

In information technology and telecommunications, Gb stands for gigabit, a unit of data equal to 1,000,000,000 bits (10^9 bits). It is commonly used to express data transfer rates and network speeds, such as 1 Gb/s (one gigabit per second). For reference, 1 Gbit per second is about 125 megabytes per second in decimal terms. Because the symbol uses a lowercase b, Gb should be distinguished from GB, which denotes a gigabyte (10^9 bytes or 2^30 bytes in binary contexts).

In genetics and genomics, Gb stands for gigabase, a length measure equal to 1,000,000,000 base pairs of DNA or RNA. It is used to describe the size of genomes and large genomic regions. For example, the human genome is commonly described as about 3 Gb in length. In this field, Gb is often encountered alongside Mb (megabase) and may be expressed as Gbp to explicitly refer to base pairs.

A practical note is that the meaning of Gb depends on context, and the capitalization of the final unit (bits versus bytes) is important. When clarity is required, terms like gigabit per second, gigabase, or Gbp may be used to avoid ambiguity.