-An OPAC (Online Public Access Catalog) is an online bibliography of a library collection that is available to the public. OPACs developed as standalone online catalogs, often from VT100 terminals to a mainframe library catalog.
-User-friendly software is exactly what it sounds like: it's a technical solution that is easy for all (or at least most) people to use to get their jobs done. This doesn't mean the software isn't complex and feature-rich behind the scenes or that anyone can step up to a computer and operate it correctly.
-You can buy ebooks from Amazon, Apple, Google, and other digital retailers, but why spend money when you can borrow them from your local library? If your library is signed up with Libby or Hoopla, you can browse, borrow, and read books directly through the app.
-Any API that requires authentication can easily switch over to JWT's authorization. With JWT authorization, you get a user-based authentication. Once the user is authenticated, the user gets a secure token that they can use on all systems. The management of the user (and therefore the token) is centralized.
-Firebase Authentication aims to make building secure authentication systems easy, while improving the sign-in and onboarding experience for end users. It provides an end-to-end identity solution, supporting email and password accounts, phone auth, and Google, Twitter, Facebook, and GitHub login, and more.