Manure and fertilizers function in the same way that is adding fertility to the soil. But they are different from each other.
Manures are obtained or prepared from natural sources like kitchen waste, vermicompost, human waste, and by decomposing the biodegradable materials. Manures are environment-friendly and are produced at a low cost. It is cost economical to farmers.
The fertilizers are synthetically and chemically manufactured in the factories and industries. Fertilizers harm the microbes present in the soil which help in nitrogen fixation and other important microbes that are useful to crop. It also decreases the soil fertility if it is prolonged and used for a longer duration. It is not cost economical for farmers.