ArcGIS Online is more than just data and maps. It also contains powerful analysis or geoprocessing tools as well. These tools can allow you to perform analysis that would normally require you to have an extension, such as calculate service areas, determine watersheds, and create elevation profiles.
As mentioned, those types of analysis typically require an extension. For example, to calculate a service area, you would need the Network Analyst extension. However with ArcGIS Pro, you can access this functionality as a ready-to-use tool without an extension. These ready-to-use tools do use credits, and typically more credits than the Infographics tool. The amount of credits used by each tool is determined by a base level for the tool plus the additional options you select that add complexity to the analysis. For example, if you needed to calculate a service area based on a simple driving distance that would use less credits than one that was based...