Quantum entanglement is a remarkable quantum phenomenon where two or more particles become fundamentally interconnected, sharing a single quantum state that cannot be described independently regardless of the distance separating them. Known as "spooky action at a distance" by Einstein, entangled particles exhibit instantaneous correlations—measuring one particle's property (like spin or polarization) immediately determines the other's, even across vast cosmic distances. This arises from their shared wavefunction, such as the Bell state (1/√2)(|↑↓⟩ + |↓↑⟩), where the particles exist in superposition until measurement collapses both simultaneously. In quantum computing, entanglement enables massive parallelism as N entangled qubits represent 2^N states simultaneously, powers quantum gates for computation, and forms the basis for error correction and quantum supremacy. While it doesn't enable faster-than-light communication due to random measurement outcomes, these perfect correlations drive revolutionary applications like quantum teleportation, ultra-secure cryptography (BB84 protocol), and the foundation of scalable quantum algorithms.