Hi
@MartaGuerrero,
See here for more information on Live Events in Microsoft Stream
https://docs.microsoft.com/en-us/stream/live-event-overviewIt is recommended to use Live Events in Stream/Teams/Yammer as Skype for Business is being phased into Teams. Currently, organisations under 500 users are being migrated by Microsoft to Teams from Skype. Ultimately, Skype for Business is being phased out of Office 365.
In terms of a Live Event compared to a video call, they are slightly different things. Whilst a video call is like a Team meeting where all members can contribute, Live Events are one to many events, such as a seminar - very similar to a Ted Talk. The limit of a Live event is much higher than a standard video call/meeting. Live Events is, broadly, the new version of Skype for Business broadcasting in the new world.
Hope that clarifies and helps to answer your question.
Best, Chris