Fis forFocal point
A focal point is where rays of light converge into a single point. The glass inside a magnifying glass is curved so that it bends all the light that goes through it towards a central point. If you move a magnifying glass up and down in the sun, you will find that at a particular distance away the magnifying glass makes a pinpoint of light that is hot enough to set something on fire. This is called the focal point.
Basking is sitting or lying in warmth, enjoying it. You can also bask in something pleasant, as in "she was basking in the attention".
Lizards like to bask in the sun because they are cold blooded and the sunshine warms them up.