This is a Buddhist song sung by children. It's a song about lighting up the candle. In Buddhism it can be said as lamp or candle. I think you can also call it as brightness instead of candle. In former times, people use candle to represent the light. Read my previous post on What does Candle/Lamp/Light mean in Buddhism?
In Buddhism, every single object can lead to enlightenment, every object in our daily life can work as reminder, too. Like when you see water, the purity of water should remind you to have a pure heart, as pure as the pure water. This is also why Buddhist followers use water instead of tea.
Ok, let's listen to this nice Buddhist song of lighting up candle.