________________ symbol is used to represent input and output operation in flowchart.

In a flowchart, the parallelogram symbol is used to represent input and output operations. This shape is specifically designated to indicate actions related to data entry or data retrieval processes. For example, when a user inputs data through a keyboard or when a system generates output for the user, such as displaying results on a screen, these actions can be represented by a parallelogram.

Additional Explanation:

Flowcharts are visual tools that outline the steps of a process or system from start to finish. Various symbols have specific meanings: ovals denote the beginning and end of a flow, rectangles represent processes or actions, diamonds indicate decision points, and parallelograms specifically indicate where data is either entered into the system or outputted from it.

Using the correct symbols in a flowchart is critical for effectively communicating the flow of information and actions within a process, making it easier for anyone to understand the operations being described. The standardization of these symbols ensures consistency and clarity in documentation.