Kuramoto Model (1975) — Each oscillator i has a phase φᵢ and natural frequency ωᵢ drawn from a Gaussian distribution. The governing equation is: dφᵢ/dt = ωᵢ + (K/N) Σⱼ sin(φⱼ − φᵢ). The order parameter r = |Σ e^(iφⱼ)|/N measures synchronization: r≈0 is incoherent, r→1 is fully synchronized. Above a critical coupling K_c ≈ 2σ_ω the system undergoes a second-order phase transition to partial synchrony. Applications: cardiac pacemaker cells, circadian rhythms, neural oscillations, power grids, and firefly flashing.