Pacman

The package manager that msys2 uses.

Also present prominently in arch linux.
Similar to apt and apt-get or dnf and yum (If you know about theses) in functionality.

For package names, having no prefix usually means that it is msys2 related. Generally speaking, this would mean that it can only be run through bash or the mintty shell (like mercurial), although there are exceptions with packages that can be run anywhere (bash, make, tar, etc. Just look through the msys64\usr\bin folder in the suite and see what has .exe appended to them. Some of the files that don't have .exe are just shortcuts or aliases to others sometimes).

Having the prefix mingw-w64 means that it's been compiled using the MinGW toolchain, with the x86_64 referring to a 64-bit version and i686 referring to a 32-bit version. This just means that it's been compiled specifically for use outside of bash etc.

For the suite, it is recommended to use do_pacman_install <pkg-name[s]> without the prefix for MinGW packages

Common commands:

• pacman -S <pkg-name[s]> install package from msys2's repository.
  • pacman -S mingw-w64-x86_64-opencl-icd-git
• pacman -Syu update the package repository database and upgrade any available packages
  • pacman -Syyuu force update the database and allow upgrades and downgrades (In case a version is found to be unstable/corrupt/or even just buggy)
• pacman -Ss <pkg-name[s]> search for a package in the msys2 repository.
  • Alternatively, if you really are that lazy/just want to see the source, https://github.com/msys2/MINGW-packages and https://github.com/msys2/MSYS2-packages

For others commands, I would recommend you to look at the arch linux wiki for pacman

https://wiki.archlinux.org/index.php/Pacman