Speaking in Tongues

What does speaking in tongues mean? Some people search for videos about "Pentecostal preaching gone crazy", so the same people can have a laugh at how ridiculous some Christians look when they are supposedly speaking in "heavenly language tongues". The truth is that there is a a big misconception (both in the churches and in non religious people too) about speaking in tongues or the technical name of, Glossolalia. The two are not necessarily the same, but they both serve a purpose, and so it's important to know the difference in order to overcome emotionalism and pride, whilst at the same time experiencing the gifts of the Spirit.