The phrase "close collaboration" refers to a working relationship between two or more parties that involves frequent communication, coordination and cooperation in order to achieve common goals. It implies a high level of interaction and engagement among those involved, with an emphasis on open communication, trust and mutual respect. In such a partnership, the individuals or organizations work closely together, sharing information, ideas and resources to accomplish their objectives effectively. The goal is usually to create something new or achieve better results by combining efforts, expertise and perspectives in a coordinated manner. Close collaboration can lead to increased efficiency, productivity and innovation, as well as stronger relationships among the participants.