A kilobit is 10 ^ 3 or 1,000 bits.
A kilobit (which can be abbreviated to “Kb”) contains one thousand bits, and as such, there are about 1,000 kilobits in a megabit.
Kilobits (Kb) are much smaller than kilobytes (KB) because a single kilobyte is formed by mixing 8 kilobits. Therefore, a kilobit is the one-eighth size of a kilobyte.
Before broadband Internet Connection, Internet connection speed was often measured in kilobits. For example, a 28.8K modem can receive up to 28.8 kilobits per second (Kbps). At the same time, a 56K modem can receive data up to 56 Kbps.
Most ISPs now offer connection speeds of around 10 Mbps or more, so the use of kilobits is the same as nowadays.
But if you download a file from a server that does not have much bandwidth, your system might receive data at speeds of less than 1 Mbps. In such a case, download speed is displayed in kilobits per second.
Where kilobits are used to measure data transfer rates, kilobytes are used to measure file size.
So if you download an 800 KB file at a speed of 400 Kbps, it will take about 16 seconds (not 2). This is because 400 kilometres per second is the same as 50 kilometres per second.