Random sample is a sample for which every member of an entire population has the same chance of being selected.
Definition Two:
Random sample is a sample of a research study population in which each individual in the population has an equal chance of being selected.
Random sample is a sample chosen at random from a population (i.e. where everyone in a whole population has an equal chance of being chosen) so that inferences can be made to the population from findings about the sample without the dangers of a biased sample.