The Operators category in the Node Graph Editor window contains nodes that provide various operations on incoming data. 

Binary Math Operation

This node outputs a float value that is the result of the specifiied operation performed on argument A and B. 

Boolean Logic Operator

This node accepts two boolean values (Input A and Input B). It will return a true value if the Logical Operator performed on Input A and Input B is met. 

Float Relational Operator - 

This node accepts two float value inputs. It will return a true value if the Relational Operator specifications are met.

Int Relational Operator - 

This node accepts two integer value inputs. It will return a true value if the Relational Operator specifications are met.

Range

This node accepts a float input and limits the input to the spcecified Input Min and Input Max. The value is then remapped to the specified Output Min and Output Max.

Rotate

This node outputs a vector float value based on the Vector, Axis, and Angle (Radians) parameters.

Unary Math Operation

This node provides three float values and outputs a result based on the Operation parameter.