Formula Area contains three main windows.
Report fields contain all database fields accessible for your report. They also contain any formulas or groups already created for the report.
Functions are pre-built procedures that return values. They perform calculations such as AVERAGE, SUM, COUNT, SIN, UPPERCASE and so on.
Operators are the “action verbs” you use in formulas. They describe an operation or an action to take place between two or more values. Examples of operators: add, subtract, less than and greater than etc.