Within the past two years, camera makers (especially Sony) have begun to add in camera wifi to their cameras. In a nutshell, in camera wifi allows the photographer to establish a wifi signal with the camera, that then is used to transmit images to a smart phone, tablet, or computer, typically through an app. This wifi is not a hotspot, allowing you to use the internet, rather it is a low signal wifi setup that allows for wireless picture transfer. The camera will then downsize the photo file to a few megapixels and save it to your camera roll. From there, you can upload to Facebook, Instagram, and the like.
I think in camera wifi is an incredibly important feature. Since smartphones can upload photos immediately, a DSLR should too. In the vast majority of cases, the DSLR is going to give you a much better image than a smartphone. So, if you can upload a better photo easily, your social media photos will be better to begin with if you shoot them with a DSLR. In a practical sense, imagine you are shooting a football game on a Friday night. You've just taken an amazing shot. Without wifi, people will have to wait to see your shots until later. Sometimes a day or two later. With wifi, you can upload your best photo each quarter, or right after that cool touchdown shot you took, and it can be shared instantly during the game itself.
Another way I love wifi is when shooting portraits. You can allow the client (or friend/family member) to view the photos periodically and they can upload a small jpeg to their Facebook/Instagram/Twitter. It makes them happy to have something immediate, but it helps you to know what types of images resonate with them personally. I use that information to tailor the shoot and to process their favorite images first.
Wifi in camera is super helpful and fun to use. It provides instant feedback and countless possibilities. Some brands, namely Canon and Nikon, are slow to this game. They have "dongles" that attach to their cameras that allow wireless transfer, but then get in the way of the user ergonomically. If you can find a good DSLR with in camera wifi, it can really be a game changer. Personally, I use a Sony a77ii for my usual camera and love the wifi. Give it a shot.