What does 3kb means?
In computing, 3 kb means 3 kilobits, or approximately 3,000
bits.
More precisely, 1 kb is 1024 bits and not 1000 bits because of
the way in which computer use binary to store data.
So, 3 kb is 3096 bits of data. It's an amount of data. You can
divide the number of bits by 8 to determine the number of bytes of
storage.
Many people write kb when they really mean to write kB. kB means
kilobytes.
Also some people make the mistake of writing kb when they really
mean kbps, or kilobits per second, which is a rate of transferring
data.