A monomial is a mathematical expression that consists of a single term. It can be a number, a variable, or a product of numbers and variables raised to non-negative integer powers. For example, 3x^2 and 5 are both monomials. Monomials do not include addition or subtraction, making them simpler than polynomials, which can have multiple terms. In algebra, monomials are often used in various calculations, including multiplication and division. They can be combined with other monomials to form polynomials. Understanding monomials is essential for solving equations and working with expressions in algebra and calculus.