What do we need installations for?

Question

This is a conceptual question and I hope it fits into Stackoverflow's question and answer style. I wonder what the concept of installing applications is good for. In my naive understanding of operating systems we do not need a registry and to use an application it should be enough to just copy the executable and files onto your drive and launch that.

Am a Windows user but also worked with Linux a bit and noticed that there are package managers instead of installers. But even those do more than just a copy instruction, I guess.

I do not think that all the installers exist only because the common user expects them out of steady habit. So what is the advantage of installers in contrast to developing applications which are designed to run out of a single folder and copy that over?

I would really like if someone could explain that concept.

Answer 1

Installing applications is a way to embed them in the OS. It's a kind of standard, you offer procedures like installing and uninstalling that should have the same functionalities for all applications (even "change" under Windows). Countless times I've "installed" applications with a single shell script that came with them, and then had troubles removing such programs, having to look for single files. If the programmer uses the standard of the OS to make an executable that can be installed, that won't happen. You can also easily view a list of the installed programs at any time. Under Linux, additionally, if we're talking about a package manager, it is convenient for the user to have an easy way to download and install a program by just typing its name.

Last but not least, some applications are required to be installed and recognized by the OS (for example services in Windows).