Welcome to Frontity
That’s right, but I’ll add some clarifications. When using Frontity, your frontend is entirely built in React and it’s isolated from your WordPress installation. Your React application (built with Frontity) will get the content from your WordPress using the REST API.
So you will have two different stacks. Your WordPress as the backend, running on a PHP server that will manage the content and Frontity as the frontend, running on a Node JS server.
This also means that the PHP rendering engine of your WordPress won’t have any functionality.
On Github you have the source code. But in order to use it, you’ll have to download it from npm. F1, or any other Frontity theme, are node packages that is available in npm.
As I mentioned above, when you want to use Frontity, you are creating a whole stack based on React that will take care of your frontend. This stack will run on a Node JS server.
I totally understand your questions and confusion. Frontity themes can’t be installed like regular WordPress themes under the wp-content/themes folder. As I explained above, you are going to use WordPress in a “decoupled/headless” architecture.
I hope this clarifies a bit more your ideas about Frontity