The term "p-adic" refers to a system of number theory that extends the concept of integers and rational numbers. It is based on a prime number p and involves a unique way of measuring the distance between numbers. In this system, numbers are expressed in a base related to p, allowing for a different perspective on convergence and limits compared to traditional real numbers. In p-adic analysis, numbers are represented as infinite series, where the coefficients are determined by their divisibility by p. This approach is useful in various areas of mathematics, including algebraic geometry and number theory, as it provides insights into the properties of numbers and their relationships in a modular context.