OS setup scripts (linux)?

Question

linux

I recently learned from such a thing as scripts for setting up the OS (we were talking about Linux). I want to know more about what it is.
Just scripts that put the right software after installing the system? Or do they work during the installation process? What language are they written in? What do you need to know for this? Where can I read about such scripts?
I want to update Ubuntu, install from scratch, so I'm interested.

Answer 1

bash seems to be what you are looking for.

Answer 2

www.pcweek.ru/foss/article/detail.php?ID=163878 this is for Suzy. for other distributions, too =). if you vrug about it