-How to download and install (build/compile) programs from source/Github
(Arch: build package (makepkg using PKGBUILD), install package using pacman)

>https://www.howtogeek.com/428988/how-to-install-software-using-git-on-linux/
Creating a computer program:
Source code ---------> Executable
  (text)     compiler   (binary)

Source code: instructions that make up a computer program
Executable: version of the program that can actually run on a computer

>https://thoughtbot.com/blog/the-magic-behind-configure-make-make-install
Generic steps to build and install a program from source:
1. Configure
    -make sure all dependencies are available
    -establish that a compiler in the requisite language (e.g., C) is present
2. Build
    -build the software following the instructions in the makefile
3. Install
    -once the software is built and ready to run, copy the built program, libraries, and documentation to the correct locations, e.g.:
        program binary to directory on PATH
        program manual page to directory on MANPATH
        other files in the appropriate locations
        
Building a program from source on Arch Linux:
1. Clone repository.
2. Create PKGBUILD to tell the compiler how to build the code.      ->  step 1, configure
3. Build package using makepkg.                                     ->  step 2, build
4. Install package with pacman.                                     ->  step 3, install

The steps listed above for Arch use PKGBUILD, makepkg, and pacman instead of the typical "configure" shell script and "make"/"make install" terminal commands, but they do the same thing; as usual in Linux, there are multiple ways to do things.