How does 𝐆𝐨𝐨𝐠𝐥𝐞 𝐀𝐮𝐭𝐡𝐞𝐧𝐭𝐢𝐜𝐚𝐭𝐨𝐫 (or other types of 2-factor authenticators) work? Google authenticator is commonly used for logging into our accounts

How does 𝐆𝐨𝐨𝐠𝐥𝐞 𝐀𝐮𝐭𝐡𝐞𝐧𝐭𝐢𝐜𝐚𝐭𝐨𝐫 (or other types of 2-factor authenticators) work? Google authenticator is commonly used for logging into our accounts