The paper presents a systematic theory for the scaling of the Nusselt number ($Nu$) and Reynolds number ($Re$) in Rayleigh-Bénard convection, which is compatible with recent experimental data. The theory assumes a coherent large-scale convection roll ("wind of turbulence") and is based on dynamical equations in both the bulk and boundary layers. The authors identify several regimes in the Rayleigh number ($Ra$) versus Prandtl number ($Pr$) phase space, depending on whether the boundary layer or the bulk dominates the global kinetic and thermal dissipation. The crossover between these regimes is calculated. For the regime most frequently studied experimentally ($Ra \lesssim 10^{11}$), the leading terms are $Nu \sim Ra^{1/4}Pr^{-1/8}$ and $Re \sim Ra^{1/2}Pr^{-3/4}$ for $Pr \lesssim 1$, and $Nu \sim Ra^{1/4}Pr^{-1/12}$ and $Re \sim Ra^{1/2}Pr^{-5/6}$ for $Pr \gtrsim 1$. In most measurements, these laws are modified by additive corrections from neighboring regimes, leading to an apparent larger (effective) $Nu$ vs $Ra$ scaling exponent. The most important neighboring regimes are the Kraichnan regime ($Nu \sim Ra^{1/2}Pr^{1/2}$, $Re \sim Ra^{1/2}Pr^{-1/2}$ for medium $Pr$), the small $Pr$ regime ($Nu \sim Ra^{1/5}Pr^{1/5}$, $Re \sim Ra^{2/5}Pr^{-3/5}$), the large $Pr$ regime ($Nu \sim Ra^{1/3}$, $Re \sim Ra^{4/9}Pr^{-2/3}$), and the very large $Pr$ regime ($Nu \sim Ra^{3/7}Pr^{-1/7}$, $Re \sim Ra^{4/7}Pr^{-6/7}$). The theory also predicts a linear combination of the 1/4 and 1/3 power laws for $Nu$ with $Ra$, $Nu = 0.27Ra^{1/4} + 0.038Ra^{1/3}$, which mimics a 2/7 power law exponent over a wide range. For very large $Ra$, the laminar shear boundary layer is expected to break down through nonnormal-nonlinear transition to turbulence, leading to a new regime. The theory is summarized in a phase diagram, which shows the different regimes and their boundaries.The paper presents a systematic theory for the scaling of the Nusselt number ($Nu$) and Reynolds number ($Re$) in Rayleigh-Bénard convection, which is compatible with recent experimental data. The theory assumes a coherent large-scale convection roll ("wind of turbulence") and is based on dynamical equations in both the bulk and boundary layers. The authors identify several regimes in the Rayleigh number ($Ra$) versus Prandtl number ($Pr$) phase space, depending on whether the boundary layer or the bulk dominates the global kinetic and thermal dissipation. The crossover between these regimes is calculated. For the regime most frequently studied experimentally ($Ra \lesssim 10^{11}$), the leading terms are $Nu \sim Ra^{1/4}Pr^{-1/8}$ and $Re \sim Ra^{1/2}Pr^{-3/4}$ for $Pr \lesssim 1$, and $Nu \sim Ra^{1/4}Pr^{-1/12}$ and $Re \sim Ra^{1/2}Pr^{-5/6}$ for $Pr \gtrsim 1$. In most measurements, these laws are modified by additive corrections from neighboring regimes, leading to an apparent larger (effective) $Nu$ vs $Ra$ scaling exponent. The most important neighboring regimes are the Kraichnan regime ($Nu \sim Ra^{1/2}Pr^{1/2}$, $Re \sim Ra^{1/2}Pr^{-1/2}$ for medium $Pr$), the small $Pr$ regime ($Nu \sim Ra^{1/5}Pr^{1/5}$, $Re \sim Ra^{2/5}Pr^{-3/5}$), the large $Pr$ regime ($Nu \sim Ra^{1/3}$, $Re \sim Ra^{4/9}Pr^{-2/3}$), and the very large $Pr$ regime ($Nu \sim Ra^{3/7}Pr^{-1/7}$, $Re \sim Ra^{4/7}Pr^{-6/7}$). The theory also predicts a linear combination of the 1/4 and 1/3 power laws for $Nu$ with $Ra$, $Nu = 0.27Ra^{1/4} + 0.038Ra^{1/3}$, which mimics a 2/7 power law exponent over a wide range. For very large $Ra$, the laminar shear boundary layer is expected to break down through nonnormal-nonlinear transition to turbulence, leading to a new regime. The theory is summarized in a phase diagram, which shows the different regimes and their boundaries.