No worries. I am not a developer and I make many mistakes and wrong assumptions about the product everyday. We are all here to learn together.
Strapi is a content management system/backend framework. The reason for local development is, in part, that NodeJS needs to restart the server each time you modify the content model, and this isn’t practical or best practice for a remotely-hosted application. Once the application is ready for production you need to deploy the app to a web server.
The frontend is independent. Strapi is going to make all of your APIs for communicating between the frontend and backend as you develop the content model.
I made a diagram that might be more helpful. I included some links to the relevant sections of the documentation.