What is the relationship between periodic points and invariant points?
Is every periodic points an invariant point?
What is the relationship between periodic points and invariant points?
Is every periodic points an invariant point?
A periodic point is a point $p$ such that $f^m(p)=p$ for some (smallest) integer $m \geq 1$. If $m=1$, it is an invariant point (more commonly called a fixed point).
So every fixed point is a periodic point, but the converse is not true.