'Tornado in a Jar' is one of several videos available in the 'Oliver's Science Lab' series, which is part of a popular YouTube channel called Oliver's Videos. The eponymous and adorable host of the Oliver's Science Lab goes over simple science experiments that parents and kids can conduct at home using regular household materials and equipment.
In 'Tornado in a Jar,' Oliver builds a science experiment that simulates a tornado in liquid. He explains the materials that one needs -- in this case, vinegar, water, dish soap, and a jar -- and goes through how to put the experiment together. After completing it, Oliver gives the audience some fun facts about tornadoes: the different types of classifications, how tornadoes are formed, et cetera.
The educational videos are a fun way for kids to use the medium they already love (q.v. YouTube) to learn as well as be entertained.