What kind of operator is the == in the expression i == 20?

The operator "==" in the expression i == 20 is classified as an equality operator. Its primary function is to compare two values for equivalence. When you use this operator, it checks whether the value of the variable on the left side (in this case, i) is the same as the value on the right side (which is 20). If both values are equal, the expression evaluates to true; if not, it evaluates to false.

This understanding is crucial in programming and logical expressions, where making decisions based on conditions is essential. For example, in an if statement, you might use this operator to determine whether to execute a block of code depending on whether a certain condition is met. The clarity of equality comparison is vital for control flow in programming, making the equality operator a fundamental concept in the language's syntax.