Some are meant to be used at conferences, some by end-users traveling abroad, some are only suitable for web conferencing. The functionalities range from allowing multi-language webinars to one-on-one video calling and some even have the bandwidth for unlimited users, which means that they can potentially be used for stadiums of people.
In The Nimdzi Technology Atlas, we have grouped the current VIT solutions into five categories and it helps to know them before you dive in: