The "=" symbol, known as the equals sign, is used in mathematics to indicate that two expressions have the same value. For example, in the equation 2 + 2 = 4, the equals sign shows that the sum of 2 + 2 is equal to 4. It is a fundamental concept in arithmetic and algebra, helping to establish relationships between numbers and variables. In programming, the equals sign can also represent assignment, where a value is assigned to a variable. For instance, in the statement x = 5, the equals sign indicates that the variable x now holds the value 5. This usage is crucial for creating and manipulating data in various programming languages.