Note, the interface in AD is divided into "personas", e.g. 1 Designer Persona + 1 Pixel Persona. Each persona offers its own set of tools and features whereas some exist in both. This is not a matter of a specific brush purchase but a general property of the app, so there is no need for a brush developer to literally point out this attitude of the app, nor is for an online shop selling brushes or assets. For the app are many tutorials available, for different levels of user skills, separated in various topics, offered by Serif but often also by users or by commercial third parties. Another option to get info is the Affinity Help, though it is no reference manual and thus may feel incomplete it gives relevant info about its features & functions, accessible also via additional, linked topics at the end of each article. For instance: