Manual Selection Focus question

[corei5]

How can I test to focus my lens front/back? I see im trying to learn AF-mode manual selection instead of automatic but still struggling with it or more likely confused at all.

ermm just a quick question how does manual selection actually work? is it like the lens will focus where ever the red mark is?

taken earlier whilst its raining but i wasnt in the rain. mind give your comment on this image I tried to used the manual selection.
forgot to mention something like when using manual focus/selection will you put the lens focus from AF to MF?


can someone explain these modes thank you
AF-mode:
One-Shot
AI Focus
AI Servo