What is the actual source of energy?

Is it the solar energy(sun)? I think I read somewhere that it goes like this. Plants use solar energy to synthesize sugar, which they consume for energy. When herbivorous animals eat the plants, the solar energy that the plants absorbed is transferred to the herbivorous animal. When a carnivore eats the herbivore, the solar energy that the herbivore has just obtained from the plant is now transferred to the carnivore. Is this how it works?