A way to organize online objects (documents, resources…) by users, who add tags or keywords from a controlled language to describe their content and represent their subject. 

An user-defined collection of controlled terms (metadata).

Lack of ambiguity, lack of user interaction and lack of correctness.

Lack of context, lack of synonymy and lack of equivalence between terms.

y = 24.4 − 0.69x

y = 24.4 + 0.69x

y = 28.7 − x

y = −0.69 + 24.4x

Users can tag and untag data whenever they want with speed and ease, meaning that folksonomies remain current and reflect current viewpoints

A browsing strategy is extremely fruitful using social tags and folksonomies to find web resources that are of interest to them and people who have common interests