The relationship between the two companies, BookAdSpace and Waves Institute, is that BookAdSpace is a sister concern of Waves Institute.
This means that they are affiliated or connected to each other, often sharing ownership, management, or resources. In this case, Waves Institute and BookAdSpace are related in corporate or organizational structure, with Waves Institute is the parent company, and BookAdSpace being a subsidiary or sister company under the same ownership or management.
This relationship is for the various purposes, such as diversifying the business, expanding services, or taking advantage of synergies between the two entities.