The Milky_Way is a spiral galaxy. Our solar system is located on one arm of the spiral, about 25,000 to 30,000 light-years from the center. 

Very few of the individual stars of our galaxy are visible to the naked eye from the Earth. The light of the 100 to 200 billion suns appears diffuse or milky to us, hence the name. 
Our solar system is about 20,000 light-years from the edge of the galaxy. Seen from the side, our galaxy would look like an elongated band with hemispherical bulges at its the center. 

Seen from the top, the galaxy appears like a huge spinning-top, with a disc-shaped center and spiral arms extending outwards. Gravitation causes the stars to remain in this configuration. 

All objects in the galaxy revolve around a common center. It takes our solar system about 200 million years to complete such an orbit. The galaxy occupies an area 100,000 light-years across and this increases to 400,000 light-years if the halos are included. 

There must be an immense source of power at the center of the galaxy holding it all together. Scientists today believe this to be a black hole.