Speed units that is "kb/s" and "kB/s"

Bit (b) is a basic unit of information in the digital world of computers. It could be expressed by 0 (zero) or 1 (one). That is why we talk about a sequence of zeroes and ones as data accepted by computers.

A more complex unit of information is a byte (B). It consists of 8 bits.

The denotation kb/s (small letter b) denotes kilobits per second.
To be exact 1 kb/s makes precisely 1024 bits per second.

1 byte (B) = 8 bits (b)

The denotation kB/s (big letter B) denotes kilobytes per second.
As 8 b = 1 B, so the speed 256 kb/s (kilobits per second) can be counted over as 32 kB/s (kilobytes per second) and this will be the same speed. The only difference is the unit in which it is expressed.

Computer systems, in particular Windows, express speed in kB/s (kilobytes per second). Therefore during downloading we see values lower than the ones recorded in the contract. In the contract we see 256 kb/s (kilobits per second). While Windows shows 32 kB/s (kilobytes per second). The difference results from using different units.