Usually, when you want to find out something about something you can't look at all the somethings, so you look at some of them and then infer to the rest. For instance, if you were investigating the relationship between age and voting preference in the USA, you could not get every voter to answer. read more
Statistical inference is the process of using data analysis to deduce properties of an underlying probability distribution. Inferential statistical analysis infers properties of a population, for example by testing hypotheses and deriving estimates. read more