Social authentication is a popular means of validating user identity through one of the Web2 or popular authentication providers such as Google, Twitter, GitHub, Twitter, Discord, Twitch, Reddit and others. For most application users, this is a familiar, seamless and easy way to onboard a new application without having to manage different identities for using different online applications. The downside is, this is a centralized system with a handful of organizations that wield the power of authenticating who you are.
In most web applications, the authentication mechanism is triggered by either a pop-up or a redirect to the user-selected social authentication provider.
In Web3 ecosystem, the idea is to not have a single organization that owns the right to validate a user credentials but a federated or decentralized system of actors that work using blockchain like protocols to provide user authentication in a decentralized manner using encrypted, shard-ed keys which are not stored with any single entity. The onus is on the user to manage their secret keys and this is a big barrier to entry into Web3 for users that are typically used-to Web2 application like experience with easy password retrieval mechanisms.
Authentication refers to Arcana Network feature that allows dApps to onboard end users through popular social mechanisms. Besides social authentication, it also supports passwordless authentication and bring your own key.