So if you have been reading up on SharePoint Server 2013 you may have heard of people talking about communities. And you said to yourself, hold it that has been around for a while now. You just need to download this or install that and it works great.
We have built that awesome functionality in and made it simple to deploy a community space where people can find each other, share documents, discuss matters that are relevant to them, and generally act like a community. Find below some great articles about what this means in SPS 2013
Discover Answers and Share Expertise with SharePoint Communities