What comes to mind when outsourcing is mentioned? The top three things are (1) labor, (2) cost savings, and (3) a different (usually 3rd world) country.
Only 1 out of 3 assumptions though is actually a good reason for outsourcing. If you guessed at cost savings you are already ahead of the game. The first assumption is valid only upto the point that labor is an area where a firm needs to save money. For example, call centers are a good place to save money. The problem with going international is that now additional laws have to be followed, and regional sensitivity to culture and resources have to be maintained. Also by going to this country, if there is a problem getting the goods back or all the laborers go on strike, then that part of the process comes to a halt.
So what is outsourcing? it is simply a firm or any entity performing an activity with someone else without having to do it themselves (and of course paying them for it). Any firm or entity would do this because they figure they can get more value from doing with someone else than themselves. Much time is spent researching where to outsource and which part of the firm to outsource so it is not just a matter of outsourcing within the country but how much value can the firm get from doing this activity externally than internally.