The present state of the ball-lightning problem is analyzed. Observational data on ball lightning are reviewed and analyzed. Analogs of ball lightning in terms of properties are discussed. Basic characteristics of ball lightning are identified. They include a rigid framework, a chemical method of internal energy storage, and a spotty emission structure. The spottiness results from the existence of a large number of small hot zones which are responsible for the emission. Problems to be resolved are pointed out. Some models which might be of assistance here are described.