A “guide” refers to a set of instructions or procedures that are used to carry out a specific business process.
For example a restaurant using a recipe to prepare a dish (the business object) as part of their food preparation process (the business process). The recipe serves as a guide for the chefs to follow, ensuring that the dish is prepared consistently and to the desired quality every time it is ordered by a customer.
The “guide” connection links a business object to instructions or procedures that guide the execution of a business process, the “resource” connection links a business object to the specific resources needed to carry out that process.