What function does an atlas serve aside from providing maps?

An atlas serves multiple functions beyond simply providing maps, one of which is the inclusion of demographic information. This information encompasses details such as population statistics, age distributions, economic data, and other societal indicators that allow users to understand the characteristics of different regions. This added context is essential for researchers, educators, and policy-makers who require a comprehensive view of a location's population dynamics and socio-economic conditions.

The other options listed do not typically align with the primary purpose of an atlas. While an atlas may include some weather-related data, it is not generally its main focus. Similarly, cultural practices might be highlighted through geographical context, yet teaching these practices is not a direct function of an atlas. The offering of online courses falls completely outside the traditional scope of what an atlas provides. Therefore, the inclusion of demographic information is a significant and valid function of an atlas, enriching the user's understanding of geography in relation to human society.