🚀 go-pugleaf

Hi. I am genuinely confused when it comes to fonts in EmTeX. I do not know
which files are ones that can be read by the TeX compiler and which ones 
support those, etc. etc. For example, there are various files related to
fonts:

.tfm = symbol widths and other properties of a font (font metrics)
.pk = compressed font file
.pxl = font file
.gf = font file created by METAFONT
.fli = font library file

Now, I do not understand what the importance of each of these is. Does the 
TeX/LaTeX .tex compiler recognize fonts with the .tfm, .pk, .pxl, .gf, or
.fli format? Or, do the .tfm files support actual font files, such as .pxl?
So basically, I am trying to figure out which group of files (which suffix)
are fonts that I can enter in a plain ASCII document (in codes that the 
compiler will recognize as needing to alter fonts, etc.), and the compiler
will recognize the legitimacy of the files as "font files".

Thanks

-- 
    .  .      +-------------------------------+
  --|--|      | Mark Yun Wook Choi            |
   /.\ |      | janhsu@hardy.u.washington.edu |
  --|--|      +-------------------------------+