Continuty is a mathematical term that is widely use in calculus. What means by continuity? Instead of mathematical difinition of continuity let us discuss literally, what is continuity?
Consider an example, that can easily explain continuity. The ocean wave, the tide of river. The icean wave is flowing continuously.
Let an example how sunlight comes to us. Sunlight do not coming continuously. There have a discontuinty. Energy flows discontinuously just making a energy packet called photon.