Origin: Latin suffix -tion
Authentication has 3 different meanings across 1 category:
a mark on an article of trade to indicate its origin and authenticity
"The customs officer inspected the authentication stamp on the imported wine bottle before allowing it into the country."
validating the authenticity of something or someone
"The bank required me to provide a government ID for authentication before allowing me access to my account funds."
something which validates or confirms the authenticity of something
"The digital signature served as authentication for the official contract, proving it had not been altered since its creation."
In plain English: Authentication is the process of proving you are who you say you are before being allowed to access something.
"The website asks for authentication before letting you access your account."
Usage: Authentication is the process of verifying that someone's identity or a document is genuine. Use it when describing the act of confirming validity, such as logging into an account with a password or checking a signature.
The word authentication comes from the verb authenticate with the suffix -ation added to it. It entered English as a noun form describing the act of verifying something's validity.