Aperture? F?

             Some might wonder, what is that strange F in the [info] section of the camera? Don't go into auto-mode/ AF mode. It is best to learn taking picture manually.
             Back to business, aperture is the opening where the LIGHT passes into the film in the camera. Don't worry, aperture can be set in any value you like as long as it's manual.
So, in the 'F', the smaller the value of it, the greater the amount of light that enters the film.

             But there is one thing which I heard from other photographers specialized in taking close-up shots with macro lenses, they told me that setting the aperture is also one of the techniques in close-up.
If the aperture is low, only the front will get focused on.
Here's an example of what I am trying to say,

See the difference of it? 

That's all about apertures. Hard? I don't think so.