What dose iff mean when used in a biconditional statement

Hello!

A biconditional statement is when one conditional statement and it's converse is true.

A conditional statement is an "If hypothesis, then conclusion" statement.

A converse statement is an "If conclusion, then hypothesis" statement.

Looking at this, both of these statements have their hypothesis and conclusion switched.

Thus, a biconditional statement is a "Hypothesis IFF conclusion." In this statement, IFF means if and only if.

Therefore, when IFF is used in a biconditional statement, it means if and only if.