The Jacobi triple product identity is a mathematical formula that relates a series of infinite products to a sum of series. It states that the product of three infinite series can be expressed as a single infinite series. This identity is significant in the field of q-series and has applications in combinatorics and number theory. Specifically, the identity can be written as a product involving theta functions, which are special functions in mathematics. The Jacobi triple product identity helps in simplifying complex expressions and is useful in various areas, including partition theory and the study of modular forms.