Some definitions

random:
A term used in probability, relating to things that happen by chance. It means that there is no special pattern to the items or numbers that are selected or chosen, that is, they happen in a haphazard way.

random experiment:
Some process that is carried out according to a set of rules. The rules determine completely the process that we carry out, but they do not tell us in advance what the outcome of the experiment will be. A random experiment can be repeated arbitrarily often.

random number:
A sequence of randomly generated numbers, where all the numbers had an equal chance of being picked, every time. Tables of random numbers used to be printed in books, these days they're usually simulated on computers/calculators. They are used to select random samples in statistics.