A "Fixed Series" refers to a sequence of items or events that are predetermined and do not change over time. This concept is often used in various fields, such as mathematics, finance, and programming, where a specific set of values or elements is established. For example, in a mathematical series, the terms follow a defined pattern, making it easy to predict future values. In finance, a fixed series can describe a set schedule of payments, like in a fixed annuity or a loan repayment plan. These payments occur at regular intervals and remain constant, providing stability and predictability for budgeting and financial planning.