A "Greek Letter" refers to the characters from the Greek alphabet, which consists of 24 letters. These letters are often used in various fields such as mathematics, science, and engineering to represent specific constants, variables, or concepts. For example, the letter π (pi) represents the ratio of a circle's circumference to its diameter, while α (alpha) is commonly used to denote angles in geometry. In addition to their mathematical significance, Greek letters are also used in fraternity and sorority names, as well as in academic and professional organizations. Each letter can symbolize different ideas or values, making them an important part of cultural and social identity.