What is the purpose of this rectangular shape in a flowchart?

The rectangular shape in a flow chart is used to show the an undergoing process or action being taken or a task being carried out.

solution:

the auto-correct option of the auto-correct tool enables you to add and delete words that do not follow abbreviation rules because:

it is a feature that allows outlook to correct common spelling and typing errors and to replace characters with symbols. we can also can use auto-correct as a shortcut, which means we can type a small string of characters and have those characters replaced by a longer string.