Networking is creating opportunities, when more people know about your skills your chances of getting hired or being considered for a position increases.
consider this, there would be many departments in your organisation which offer a better profile than your current one. imagine a position gets vacant there, a senior knows you since you took part in company organised quiz/ played foosball/Table tennis in office ( my office has one), went to townhall etc etc…. he might recommend you name.. might…
bacially networking is marketing yourself…