A universal quantifier symbol indicating "for all" or "for every" elements in logical statements and set theory.
Examples
Basic universal quantifier in predicate logic
\forall x \in \mathbb{R}, x^2 \geq 0
Multiple quantifiers in a mathematical statement
\forall \epsilon > 0, \exists \delta > 0 \text{ such that } |x - a| < \delta \implies |f(x) - L| < \epsilon
Set theory property
\forall A, B, C: (A \cap B) \cap C = A \cap (B \cap C)