I publish a short note to explain what it is: Social Engineering is defined as a set of actions with which one tries to obtain sets of information concerning one, or more, people, usually with illicit purposes.
For example, someone can follow your computer tracks, on various social media, and also in your other public expressions on the net (forums, comments, blogs ...). In this way he can get an idea of who you are, and you can discover some of your characteristics.
By creating special fake accounts, those who do social engineering could directly talk to you, and therefore have access to further personal information.
It is not said that you are the main target of these people, but sometimes you could become one. Do you know how? I will give you an example:
The attacker could make a first generic search: he could create one or more fake accounts, create a network of friends asked at random, and from there identify the subjects less attentive to the protection of their data, Yes, because accepting friends from unknown people , denotes at least some easiness, and certainly little attention to your data. That's why this could get you into the sights of more dangerous actions, to steal your data.
In fact, every information obtained is a piece to reach other more important information.
Usually, collecting this information has illegal purposes, such as fraudulently accessing the most sensitive information, based on the data already in possession, and therefore trying to enter your e-mail / social media / profiles and everything that is possible, even in your bank accounts.