A large operator symbol representing repeated logical disjunction or the supremum of a set in lattice theory.
Examples
Logical disjunction of multiple statements
\bigvee_{i=1}^n P_i \text{ is true if any }P_i\text{ is true}
Supremum of a set
\bigvee_{x \in S} f(x) = \sup\{f(x) : x \in S\}
Join operation in lattice theory
\bigvee_{i=1}^4 a_i = a_1 \vee a_2 \vee a_3 \vee a_4