title: What do the *-dev packages in the Linux package repositories actually contain?
body: <p>My question is very basic, as is my knowledge right now.</p>
  
  <p>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. <em>pidgin-dev</em> in addition to <em>pidgin</em>). My question is this: </p>
  
  <p>What is in these packages? How does downloading <em>pidgin-dev</em> 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?</p>
  
  <p>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.</p>
  
  <p>Any and all advice more than welcome!</p>