Hi Andrew,
An action refers to a 'page' within an object and would correspond to an action for the application in use. These should be kept relatively short, to maximise re-usability.
A page in the context of a process is likely to be a collection of actions, decisions, calculations, etc. This will be a sub-section of the overall process and can be used once or multiple times within the process. For example it might be the actions to launch and log into the application or the sequence of actions to create a new record.
A key difference is that an action should not contain any business logic, as this would make it less re-usable. Where a process will contain the decisions that change how the work item is handled. Such as a different product needing to be routed down different process paths.
There's a useful course on Blue Prism University,
Development Best Practice. If the link doesn't work, simply search Development Best Practice in the courses.
Regards
Ben
Ben Lyons
Principal Product Specialist - Decipher
SS&C Blue Prism
UK based