There are two main approaches to social features in SharePoint: OOTB social features and Yammer.
SharePoint OOTB Social
There's a big hub about social collaboration in SharePoint on TechNet, including overview video.
To summarize, SharePoint has quite a number of social features OOTB:
- SharePoint users can follow sites and each other;
- SharePoint users can create posts, so that other users who follow them see it;
- It is possible to change visibility scope of a post
- It is possible to add an image to your post (only png, jpg and bmp):
- It is possible to address people just like it is done e.g. in Facebook and other social networks:
- It is possible to add links, however functionality is not same as in other social networks:
- SharePoint users can discuss posts of each other by posting replies and likes.
- There are also special community sites that provide features for organizing something similar to Facebook groups
There is also a number of videos on YouTube about the Social Feed:
But please be aware that as it very often happens with SharePoint, it can look very good at first glance, but there might be some limitations without workarounds... So I would recommend to evaluate every single feature before you decide to go with it.
There is a post from Nik Patel about social features. He lists limitations for each feature:
But I would still urge you to evaluate every feature yourself.
Yammer is a full-scale enterprise social network with a wide range of collaboration features and very deep integration into SharePoint. Yammer is included into some enterprise Office365 plans.
Here's a technet article of how you can integrate Yammer with SharePoint 2013 on-premise:
In fact, it is possible to completely replace SharePoint OOTB social with a much more developed Yammer features.
Yammer also has an API, so you can interact with it. Here is a very good article describing Yammer and SharePoint integration and use of the Yammer API from Vesa Juvonen: