The POC (Proof of Concept) is the very first brick in your project that you can use to prove its feasibility. It can be in the form of a schema, a wireframe or even an application that will have as its sole mission to tests the main functionality of your project. It should be noted that a POC is only intended to test your idea to prove its feasibility and not to deploy it to the public. It is therefore not at this stage that you should pay attention to details that are not essential to its operation.
The MVP (Minimum Valuable Project) is a functional marketable product containing the minimum features to provide a simple user experience and a concrete solution.
The V1, represents the complete solution with all the main features, a complete design, and the feedback from the MVP taken into account.