Informal Learning and Non-formal Learning are kinds of learning that happen outside the formal educational institutions and programs. Many people acces Youtube, blogs, Wikipedia, Language apps, music learning games, etc, to get new skills, new knowledge and meeting people that act as teachers in some way. 

To the OECD:

Formal learning is always organised and structured, and has learning objectives. (...)
Informal learning is never organised, has no set objective in terms of learning outcomes and is never intentional from the learner’s standpoint. Often it is referred to as learning by experience or just as experience. (...)
Mid-way between the first two, non-formal learning is the concept on which there is the least consensus (...) for the majority of authors, it seems clear that non-formal learning is rather organised and can have learning objectives. The advantage of the intermediate concept lies in the fact that such learning may occur at the initiative of the individual but also happens as a by-product of more organised activities, whether or not the activities themselves have learning objectives. ^[1]

The difference between Informal and Non-formal is that Informal happens while we do, watch, participate and live, while Non-formal has learning objetctives and states an strategy to learn. Still, I think that these two are very connected beacuse we can, for example, learn throug Informal learning that we enjoy building things and then we decide, via Non-formal learning, deepen our knowledge and skill in doing it.

Considering that formal schools are yet mostly confined by time and space, the Informal Learning is a natural expression of the human need to learn, teach, share and build, and is a demonstration of how Ubiquitous Learning actually works for many self-appointed students.

Formal education can learn a lot about how technology can be used to teach, because the Informal learners have build the space and means they like and want to learn. We should not ignore that trying ti build new contexts, wehn learners themselves had already made an statement.