When someone makes a statement investing his strong belief in it, as if it is true, though it may not be, he is making an assertion.

The behavior or attitude in response to something; an action in a reverse direction or manner is called reaction.

By using assertions in writing, writers can defend others’ feelings and rights if violated.

The purpose of assertion is to express unclear ideas or feeling indirect.

Language assertion occurs when someone is not able to give a response to a person’s basic assertion and therefore that person becomes firm about him or her.