CentOS

I need gcc, make and other essential stuff on a CentOS machine. The thing is that the machine is not (and probably will not be) connected to the internet.

Downloading the packages on some other computer, then moving and installing them here seems as an option. However, to compile packages I need make in the first place as far as I know.

What should I do? How can I get make here? How can I use yum to install packages from the local drive?

The best answer would be to create a local mirror on a machine that your disconnected machine can reach. For information on how to go about setting up a local CentOS mirror please see https://wiki.centos.org/HowTos/CreateLocalMirror

Failing that you'll have to identify each package you want, download it from a mirror, copy it to your machine, use e.g. yum --disablerepo=\* install /path/to/my/downloaded/packages/*.rpm, identify anything missing, repeat.