The planet Venus is normally referred to as the evening star because it becomes visible just when the sun is about to set. This planet is also referred to as the morning star as it sometimes can be seen shinning brightly just before the sun rises in the morning.
Venus is not really a star but one of the nine planets in the milky way. Stars are located much farther away in the galaxy than any of the planets. Another difference between stars and planets is that stars emit heat just like the sun and their own light while planets reflect light from the sun.
Venus is normally referred to as the evening star because it can be seen shining in the evening sky right after the sun sets in the west. This planet is also called the morning star when its orbital position changes causing it to appear bright in the morning rather than in the evening.
Venus is visible to people on earth because it is closer to earth than all of the other planets. It is the second closest to the sun after Mercury. Venus is also the brightest object in space after the sun and moon.