"Social networking" is defined by Merriam-Webster as, "an online community of people with a common interest who use a website or other technologies to 

communicate with each other and share information, resources, etc".

Though social networking in the digital sense began as a way to build and maintain personal relationships, it quickly expanded to the professional realm. In response, various social media platforms have been created to support not only general professional networking (e.g., LinkedIn), but also niche markets and disciplines. 

3 ways doctors can use social media today

Are Doctors Using Social Networks for Work?

The Doctor Will Tweet With You Now: Social Media for Oncologists

Doctors 2.0 & You 2015 Speaker Content: Creating a Social Media Strategy

Findings from the Pew Foundation's Internet & American Life Project on Healthcare

Share Practice releases mobile app to help good doctors become great doctors

Online Social Networking for Radiology

Online collaboration: Scientists and the social network

Photo-Sharing Without LOLCats? Figure 1 Raises $4M to Become Medicine’s Instagram