Hi MikeA01730! The new 1Password for your browser is a standalone extension that can work without the 1Password app. Because of that, this extension requires an account for use. In terms of features, this extension has an inline menu, which helps with saving and filling logins. It is also regularly updated and has a stable release as well as a beta release. You can learn more about it here: https://support.1password.com/getting-started-browser/
The classic extension is different from the new extension in that requires the 1Password app in order to run. It is still a good extension, but it is no longer receiving updates. If you have a license, then the classic extension is the one to use, as it does not require an account. That said, if you have an account or would like to sign up for one, then the new extension is the best option. If you don't have an account and would like to get started with one, please let us know, and we can help you with a special promotion for one!