Facebook's date of birth can be identified in the year in which Social Media was started as a social network service: we are talking about 2004, with the launch day on 4 February.
In Harvard (USA), some students, among them the owner Mark Zuckerberg, created a social network for their university, a sort of online directory with all the students of the Institute.
The idea was to allow the young residents to identify with each other and to identify, above all, the members of other residences.
The same name recalls the fact that Facebook wanted to be an index with information on each student, with attached photo.
It was inspired by a paper list with name and photography, distributed in some universities to help socialize among students.
There had been a previous and similar attempt in 2003, called "Facemash", a first database with student information but it was closed because Zuckerberg had gotten the student data illegitimate.
It was not the first of Mark Zuckerberg's problems, since he was accused of stealing the idea from other students who wanted to create a social network called "HarvardConnection", an accusation that led the founder of the famous Social to face a first lawsuit.
In any case, Facebook came up and in a short time most of the Harvard students registered at the site.
The current domain, facebook.com, was registered in 2005 (before 2005 the address was "thefacebook.com").
From that moment on, success increased steadily and access was gradually allowed to more and more institutions and finally to anyone who wanted to register.
First it spread to other American schools (Boston, Ivy League, Stanford University, then to high school students).
In 2006 they could use it all the more than 13 years and one year later it was already among the ten most visited sites in the world.
The year 2008 was instead the year in which Facebook users exceeded those of the famous MySpace.
And 2012 was another very important year: Facebook in this period was in effect a huge global giant and came to buy another important Social Media: Instagram.
Not only that, because 2014 came and Facebook also bought Whatsapp.
At the beginning of 2017 Facebook has almost 1.65 billion active users all over the world, of which about 1 billion connect and participate every day (note that already on August 24, 2015, one billion users registered for the first time connected simultaneously).
In 2018 the 2 billion active users were exceeded.
Needless to say that for several years now Facebook is the Social Network with the largest number of active users.