Platform for video conferences, webinars, what are they?

Question

Skype

Good afternoon,
the question of video conferencing and holding webinars within the company has ripened, they were
given the task of considering open source first, if there is no such proven system, then consider paid services,
can you advise software / resource / product / solutions for video conferencing / webinars?
respectfully

Answer 1

mconf.org
https://bigbluebutton.org
https://jitsi.org