Computer-mediated communication means that speakers have more time to engage in the conversation. They do not to respond immediately. There are delayed responses.
Social media allows people to communicate anytime and anywhere using a variety of signs and symbols.
There are also a lot of emoticons and other feeling-images. This use of images should compensate for the lack of facial expressions and body language. Indeed, social media lacks the presence of participants. The system would like the users to feel warm and happy with the feelings, so they come up with options for users to use a variety of signs and images.
The advent of the Internet and smartphone technologies makes the world smaller. The people of the 21st century, now, have the access to plenty of news and information. They make new friends and collaborate with each other. Some people spend more time online than conversing face to face.