There are two bones in each lower leg. They are the Tibia and Fibula. The Tibia is the bone in the front that is often referred to as the shin bone. The Fibula is behind the Tibia towards the back of the calf. In case you wanted to know, the smaller bone is the fibula.
The tibia is part of the lower leg. Below your thigh, (femur), and your knee,(patella), are two long bones, the tibia and the fibula. They are easy to tell apart in that the tibia is larger then the fibula. "The shin bone", is your tibia. It is slightly stronger than the fibula.