This review discusses the scaling of the Nusselt number (Nu) and Reynolds number (Re) in turbulent Rayleigh-Bénard convection as functions of the Rayleigh number (Ra) and Prandtl number (Pr). The focus is on the scaling of the thicknesses of the thermal and kinetic boundary layers with Ra and Pr. The review also addresses non-Oberbeck-Boussinesq effects and the dynamics of the large-scale convection-roll. It concludes with a list of challenges for future research on the turbulent Rayleigh-Bénard system. Rayleigh-Bénard convection is a classical problem in fluid dynamics, important in various applications such as atmospheric and oceanic flows, building ventilation, and geophysical processes. The governing equations are the Oberbeck-Boussinesq equations, which assume that the fluid density depends linearly on temperature and that material properties are constant. The system is determined by two dimensionless parameters: Ra and Pr. The key response of the system to Ra is the heat flux H from bottom to top, with Nu = H/(ΛΔL⁻¹) being the Nusselt number. The extent of turbulence is expressed in terms of a characteristic velocity amplitude U, leading to the Reynolds number Re = U/(νL⁻¹). The review discusses various theories for Nu and Re, including older theories and the Grossmann-Lohse (GL) theory, which provides a unifying framework for Nu and Re over wide parameter ranges. The GL theory is based on exact relations for the kinetic and thermal energy dissipation rates, which are split into bulk and boundary layer contributions. The theory predicts scaling laws for Nu and Re, with different regimes depending on the relative contributions of the bulk and boundary layers. The theory has been validated against experimental data and provides predictions for Nu and Re over a wide range of Ra and Pr. The review also discusses the structure and width of the thermal and kinetic boundary layers, the role of thermal plumes, and the dynamics of the large-scale convection-roll. It addresses non-Oberbeck-Boussinesq effects and the global wind dynamics, and outlines major issues for future research in Rayleigh-Bénard convection. The review concludes with a discussion of the asymptotic regime for large Ra and strict upper bounds for Nu.This review discusses the scaling of the Nusselt number (Nu) and Reynolds number (Re) in turbulent Rayleigh-Bénard convection as functions of the Rayleigh number (Ra) and Prandtl number (Pr). The focus is on the scaling of the thicknesses of the thermal and kinetic boundary layers with Ra and Pr. The review also addresses non-Oberbeck-Boussinesq effects and the dynamics of the large-scale convection-roll. It concludes with a list of challenges for future research on the turbulent Rayleigh-Bénard system. Rayleigh-Bénard convection is a classical problem in fluid dynamics, important in various applications such as atmospheric and oceanic flows, building ventilation, and geophysical processes. The governing equations are the Oberbeck-Boussinesq equations, which assume that the fluid density depends linearly on temperature and that material properties are constant. The system is determined by two dimensionless parameters: Ra and Pr. The key response of the system to Ra is the heat flux H from bottom to top, with Nu = H/(ΛΔL⁻¹) being the Nusselt number. The extent of turbulence is expressed in terms of a characteristic velocity amplitude U, leading to the Reynolds number Re = U/(νL⁻¹). The review discusses various theories for Nu and Re, including older theories and the Grossmann-Lohse (GL) theory, which provides a unifying framework for Nu and Re over wide parameter ranges. The GL theory is based on exact relations for the kinetic and thermal energy dissipation rates, which are split into bulk and boundary layer contributions. The theory predicts scaling laws for Nu and Re, with different regimes depending on the relative contributions of the bulk and boundary layers. The theory has been validated against experimental data and provides predictions for Nu and Re over a wide range of Ra and Pr. The review also discusses the structure and width of the thermal and kinetic boundary layers, the role of thermal plumes, and the dynamics of the large-scale convection-roll. It addresses non-Oberbeck-Boussinesq effects and the global wind dynamics, and outlines major issues for future research in Rayleigh-Bénard convection. The review concludes with a discussion of the asymptotic regime for large Ra and strict upper bounds for Nu.