How is the deployment of web applications after working through Docker?

Question

Backend

I recently started learning docker because my current job requires it and I have a few questions. As I understand it, docker is used as a small virtual machine, on which developers throw their back and host on the same small virtual machine. Question: when it comes to deploying to a production server, is the image simply copied and run on the server via docker? That is, the server, as it were, hosts another small virtual server on which this same web application runs? And if there are many developers, each of them has their own containers and each of them makes a change to some part of the application, then how are such containers synchronized?