A Geometric Progression (GP) is a sequence of numbers where each term after the first is found by multiplying the previous term by a fixed, non-zero number called the common ratio. For example, in the sequence 2, 6, 18, 54, each term is multiplied by 3 to get the next term. Geometric progressions are widely used in various fields, including finance, physics, and computer science. They help model exponential growth or decay, making them essential for understanding concepts like compound interest and population growth. The formula for the nth term of a GP is given by a_n = a * r^(n-1), where 'a' is the first term and 'r' is the common ratio.