The core activity of the company "Elektrogenossenschaft Oberrüti" encompasses three main areas: 1. **Energy**: The company is active in energy supply, although no specific details are mentioned regarding the type of energy supply (e.g. electricity, gas, heat). 2. **Network**: The "Network" area likely refers to the infrastructure for energy and telecommunications supply, such as power and fiber optic cables. 3. **Telecommunications**: The company offers telecommunications services, particularly in the area of fiber optic and coaxial distribution networks, including FTTH (Fiber to the Home) solutions.