The symbol "\sigma" represents summation in mathematics, indicating the process of adding a sequence of numbers. It is often used to simplify the expression of adding multiple terms, such as in series or sequences. The general form is \sum_i=a^b f(i), where i is the index of summation, a is the starting value, b is the ending value, and f(i) is the function being summed. Summation is a fundamental concept in various fields, including calculus, statistics, and computer science. It allows for efficient calculations and is essential in formulas for averages, totals, and other mathematical analyses. Understanding summation is crucial for working with data and solving problems involving series.