im studying about photography on the internet and i have some theoretic questions while i know how it works on application

F-number - Wikipedia, the free encyclopedia

article:

according to the previous quote, i understand (im not british though so my english are ><) that f-number=f/Dthe f-number is the focal length divided by the "effective" aperture diameter......

.....The f-number is given by "f/D" where f is the focal length, and D is the diameter of the entrance pupil

and that when we see "f/8", that means that the f-number is "f/8", that is, not just "f" or just "8"

an img at the top right reads as following: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8

and the note below reads the following:

questions:Diagram ofdecreasing apertures, that is,increasing f-numbers, in one-stop increments; each aperture has half the light gathering area of the previous one.

1) but on the image, "f/2" is a number higher than "f/4" for example since the denominator is lower, so how are these "increasing f-numbers" since the second number is lower?

2) if the f-number is the focal length divided by the "effective" aperture diameter (i know it's not (always) the hole of the pupil and not even the hole of the blades but the aperture "bottleneck" point of the final idol - lets not get into that), how come the "f/1.4" represents the higher aperture? the aperture ('s diameter and thus the aperture) is the denominator right (remember? "f/D") ? so the denominators are 1.4, 2 ..., 8 and 8 is the higher one, not 1.4

as i said im not british and im kind of sleepy, but i can't go to sleep until i found out what's going on

my next question is pretty predictable

3) am i misunderstanding something, or is the f-number actually not an officially defined term and is actually the number the photographers use when they are referring to their cameras' setting for the aperture and thus in "f/8", is the "8" part? cause that would explain all the above

thank you for your time