Mathematical induction is a proof technique used to establish the truth of an infinite number of statements, typically involving natural numbers. It consists of two main steps: the base case and the inductive step. In the base case, you prove that the statement holds for the first natural number, usually 1. In the inductive step, you assume the statement is true for some natural number k and then show it must also be true for k + 1. This method is particularly useful for proving formulas, inequalities, or properties related to sequences and series. By confirming the base case and the inductive step, you can conclude that the statement is true for all natural numbers, thus demonstrating its validity across an infinite set.