Inferential statistics are often used with large amounts of data that is taken from the general population. If the idea or mood of the public needs to be gauged on a subject or the viability of a product needs to be evaluated a smaller test group of subjects will be considered. Inferences will be drawn from the overall information that will be contained in the compiled answers.
A good example of this is when a product states that some percent of users have been satisfied or some other piece of information is being qualified through facts. Census information is often used to draw inferential statistics about the demographics of a population relating to how much money they earn, the level of disposable income, the education level, how many own phones or laptops etc.