ubuntu - What do the *-dev packages in the Linux package repositories actually contain?

Question

My question is very basic, as is my knowledge right now.

I'm a long-time Linux user, but have only recently taken a major interest in programming. I see that many popular applications in the Ubuntu repositories have -dev packages (e.g. pidgin-dev in addition to pidgin). My question is this:

What is in these packages? How does downloading pidgin-dev help one to develop for Pidgin? Is it as simple as a dependency check for the tools necessary to create the plugins for the given application?

I was hoping there would be a substantial amount of documentation in the -dev packages, but if there is, I can't figure out how to access it. I'm thinking of something like a man-page, but useful for editing code.

Any and all advice more than welcome!

Answer 1

The *-dev packages most often contain the headers related to a library's interface. Next most common are package-config files (*.pc) describing build options and staticly linked libraries.

In general, if you want to know the contents of a package you have installed, dpkg -L pkgname will get you that. The apt-file program can tell you the same for any package in the repositories.

Note, also, that the answers by William Pursell and caf contain useful additional details. If you find their input helpful, do upvote it.