Numerical simulation of flames is a growing field bringing important improvements to our understanding of combustion. The main issues and related closures of turbulent combustion modeling are reviewed. Combustion problems involve strong coupling between chemistry, transport and fluid dynamics. The basic properties of laminar flames are first presented along with the major tools developed for modeling turbulent combustion. The links between the available closures are illuminated from a generic description of modeling tools. Then, examples of numerical models for mean burning rates are discussed for premixed turbulent combustion. The use of direct numerical simulation (DNS) as a research instrument is illustrated for turbulent transport occurring in premixed combustion, gradient and counter-gradient modeling of turbulent fluxes is addressed. Finally, a review of the models for non-premixed turbulent flames is given.