Google Sign-In allows users to sign in to your application with their Google accounts
OAuth (short for "Open Authorization") is an open standard for access delegation, commonly used as a way for internet users to grant websites or applications access to their information on other websites but without giving them the passwords.
Reputation is a measurement of a user's contributions to the site, and the extent to which the community "trusts" that user with extra privileges.
SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine.
macOS (previously OS X and originally Mac OS X) is an operating system developed and marketed by Apple Inc.