In the modern world, people communicate via telecommunications much more often than in the real life situations. Online and offline communication complement each other as much as the written speech supplements the oral.
Since olden times, communication (speech, smile, look, gesture, etc.) has been based on the live mediators like messengers and pigeons, and especially on the non-living ones like a chain of bonfires, a bottle with a note thrown into the ocean, postal service, telephone and all the current telecommunications.
Mediators transmit mainly the written language (notes). In the course of modern life, we mostly transmit our speech by means of telephone, Skype, and social networks.
Internet VS reality
Typically, communication is an exchange of information. In this case, the online form wins: it allows attaching a document, an image, or an audio file, and the message becomes quite reasonable. However, in communicating online it is easy to miss an angry look or a wry grin of the recipient.
The dominance of online communication reduces the development of the emotional intelligence, the ability to express emotions and to understand other people. Smileys help but only partly.
Online communication does not strengthen strong relationships like love, friendship, or neighborhood; however it intensifies the weaker bonds (subscribers and followers). People often get acquainted online, join on-line communities, and participate in different promotions.
Offline model does not make mass flash mobs that achievable. In some cases, distant relationships develop into personal: online communication really complements the offline one. On the other hand, the weak ties do not last for a long time...
Perception of a person by a person
Since the ability to give feedback is limited, the online mode allows people to "embellish" their biography, experience, skills, and present themselves accordingly, choosing the appropriate avatar. Most of the young people prefer to get acquainted in the web which gives them more self-confidence and space for communication. Surely, it is much easier and faster to get a basic information about a person when you examine his/her Facebook profile first.
Online communication is a powerful tool of manipulation and trolling. However, more and more people give up modern notions and prefer to remain themselves online. When your images online and offline do not contradict, but complement each other, there is a harmony, and it is the most sensible style of communication.