The Existential Quantifier is a symbol used in logic and mathematics to express that there exists at least one element in a given set that satisfies a certain property. It is typically denoted by the symbol ∃. For example, the statement "There exists an x such that P(x) is true" means that at least one value of x makes the property P true. In formal logic, the existential quantifier helps in making assertions about the existence of elements without specifying which ones. This is useful in various fields, including mathematics, computer science, and philosophy, where understanding the existence of solutions or objects is crucial for reasoning and problem-solving.