Our team is split across 3 locations, so it was always a challenge to organize meetings. We switched to Zoom close to two years ago for this, and it solved our problems perfectly. You schedule a meeting and send everyone invites. It integrates with Outlook so all those invites come with a calendar attachment. I really love the simple, easy to use interface of Zoom. It is also really easy to join meetings. We have used it to set up meetings from multiple locations and can't remember the last time someone couldn't join it.
It also works really well even if your internet speed is slow. Some of our staff members work from remote locations with not the best internet speed, and it still worked perfectly with clear audio and video under those conditions.
The collaboration tools built in are really useful too.
Overall it's a really well-rounded software with a ton of features.