Elliptical

Shaped like an egg.


Source
www.math.uri.edu

Orbit

To move around a circle in a round or elliptical motion. To make a complete motion around the sun.


Revolve

To rotate around, to move around the sun. Simiiar to orbit but anyone can rotate. You can rotate your body. Orbit is usually used when talking about space.


Solar

Having to do with the sun. It is called the "solar" system because everything rotates around the sun.