The diagrams demonstrate how the solar panel is formed and on what purposes it is used. Overall, it can be seen that there is one of three diagrams showing the form of solar panel and the other two depicting two various aims of using that panel for, namely for absorbing sun rays to make warm air and water.
First of all, taking a look at the structure of solar panel, which is rectangular with two tubes called inlet and outlet on different corners which air and water pass through, as well as a glass sheet on the top which makes easy to absorb rays. As for the panel which is made to warm air, air comes firstly from inlet tube to inside and gets warm with the help of rays coming from the top, and leaves there through outlet part.
The same process works for the other panel which is slightly different from the previous one. Water comes and goes out from the same inlet and outlet tubes. However, that panel has got transmission pipe which is in zig-zag shape laying down inside the panel. That pipe consumes heat energy coming from sun through glass and provides heat with water. Then, it also gets warm eventually.