Personal Computers

For "personal computers", which I am defining as the sort of computers that have a keyboard and a screen, the most common operating system is Windows. The second most common is Mac OS.

These are both produced by massive corporations in order to sell pre-installed on computers. As such, they give you a graphical interface that you navigate with a mouse/touchpad and keyboard. This is what people have found comfortable and what most are used to.

To write code and do other programmer things you have to install programs but once you know what you need to install its pretty easy.