This things are annoying. They give you a place in station that you can go to and do stuff. It, however, with enough effort is destroyable. It is called POS bashing because they have a ridiculous amount of EHP (Effective hit Points) and can take hours to shoot. They were what drednoughts were made to destroy.
It still sucks, horribly. Its just mindless grinding. The hope is that people will come and defend their POS. However, this corp keeps not.
However, the big ships are cool.
In our home system we bashed a Concord owned POCO (player owned customs office) just to test out the newest drednought to the corp.
Nice, big fleet.