Focus
Noun and の adjective
しょうてん
先生が顕微鏡の焦点の合わせ方について説明をしてくれていた時、私は上の空でした。
When our teacher explained how to focus the microscope, I was spacing out.
The char point is the part you're looking at so hard it burns a little hole in it. Just imagine yourself looking at a single point so hard that it begins to smolder. This is the focal point or the focus.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.