What is what does sum mean?

The sum is a mathematical term that refers to the addition of two or more numbers or quantities to obtain a total amount. It is represented symbolically by the "+" sign and can be calculated using various methods such as mental math, long addition, or computer programs. The sum of a set of numbers can also be expressed in terms of a mathematical formula or series, such as the arithmetic progression, geometric progression, or Fibonacci sequence. In addition to being useful in basic arithmetic and algebra, the concept of summation is used throughout higher-level mathematics, engineering, science, and statistical analysis to calculate averages, probabilities, and other quantitative measures.