In this project we explore how the CMB and matter power spectrum varies as function of the cosmological parameters, and what is the observational data available to compare with. Using the Cosmic Linear Anisotropy Solving System (CLASS) and the $\Lambda$-CMB model (with curvature zero), the following cosmological parameters were varied: the Hubble parameter (h), the CMB temperature ($T_{CMB}$), the baryon density ($\Omega_{b}$), and the CMB density ($\Omega_{CMB}$) (although the curvature density was also varied individually for small values). Of each parameter, 5 variations were obtained individually and the graphs of the mass and CMB power spectrum were generated. Similarly, the parameters (h and $\Omega_{b}$), ($T_{CMB}$ and $\Omega_{CMB}$), and ($\Omega_{b}$, $T_{CMB}$, and $\Omega_{CMB}$$) were varied. The variation of multiple parameters allowed us to conclude that, in general, the power spectrum is more sensitive to $T_{CMB}$ and $\Omega_{CMB}$ parameters.