Reflect means to bounce off something.  A mirror reflects our image.  Light can reflect off a planet.

The Sun makes light.  A candle and a fire can make light.  A lightbulb can make light.  Light fills a room and makes it so we can see.

A ball can bounce.  Drop it to the ground and it comes back.  Light can bounce.  Point a flashlight at a mirror.  The light will bounce and go to another part of the room.

The Sun is a star.  The sun is very, very, big.  The Sun is in space.  The Sun is very, very hot.  The Sun is made of burning gas!

A planet is made of rock.  A planet is very, very big.

The sun gives off heat and light.  This is called sunlight.