Two Factor Authentication
Two Factor Authentication is a security measure that, rather than just using a password, also uses a second method of validation typically by text message or phone call. This adds a second layer of security and prevents breaches caused by weak or exposed passwords.
Two Factor Authentication is available as standard within Office 365 subscriptions and as add-ons within Microsoft Azure and ESET. This extra layer of security is advisable to verify personnel access for Virtual Private Networks, Virtual Machines and Virtual Servers.