Epidemiological modellers integrate mathematical modelling, statistical inference, and biological parameters to simulate disease spread, estimate reproduction numbers, evaluate intervention strategies, and forecast outbreak trajectories. They use compartmental models, agent-based simulations, Bayesian inference, and real-world health datasets. Their work supports public health agencies, hospitals, research institutes, and global disease surveillance programmes. They collaborate with epidemiologists, health economists, policymakers, and data scientists. Increasing frequency of emerging diseases and need for preparedness modelling make this one of the fastest-growing scientific fields.