Is there a conference software like Zoom, but in such a way that you can participate by video and telephone?

Does anyone of you know of a (freeware / open source) software that you can participate in via video or alternatively only by telephone? So that some participants (with laptop / smartphone) can take part by video and others who do not have a smartphone or the like can only take part by phone? (Zoom out - only works with smartphone / laptop / tablet).

As far as I know, this is possible with Cisco Webex

Awesome, how fast it went:-) Thank you very much, I'll have a look. Is it free and easy to understand? (Boomer alarm:-)

Freeware / open source is a problem, someone has to operate the telephone system. But you can use Cisco Webex free of charge at least to a limited extent and that doesn't cost the world if the free version is not enough.

Sorry for the late reply. We use Webex in our party work, and the people who manage it are older and get along well with it. There's a free version that can talk for 50 minutes