Qubits vs Bits: A classical bit represents information as either 0 OR 1 in a definitive, stable state, serving as the binary foundation of all traditional computers through Boolean logic operations. In stark contrast, a qubit (quantum bit) leverages quantum superposition to exist simultaneously as both 0 AND 1 (α|0⟩ + β|1⟩), where α and β are complex probability amplitudes whose squared magnitudes sum to 1. This enables N qubits to represent 2^N states simultaneously—50 qubits equal 1 quadrillion classical states—providing massive parallelism for quantum algorithms. While bits remain stable without external interference, qubits suffer from decoherence, rapidly losing their quantum state unless maintained at near-absolute zero temperatures. Bits support irreversible operations and perfect copying (no-cloning theorem inapplicable), whereas qubits require unitary, reversible gates and cannot be cloned due to the no-cloning theorem. Classical computers process bits sequentially through AND/OR/NOT gates, but quantum computers manipulate entangled qubit superpositions via Hadamard, CNOT, and phase gates, collapsing to classical results only upon measurement. This fundamental dichotomy enables qubits to solve intractable problems like factoring large numbers (Shor's algorithm) and database search (Grover's algorithm) exponentially faster than bits for specific computational classes.