What is a 2FA?
2-factor Authentication aka 2FA is an approach to add another layer of security on the top of baseline layer of username and password. Generally, it is achieved by asking user to add another code when logging into a service which can be generated via a registered application (e.g. Google Authenticator, password managers, etc), sending a code to  registered mobile number or email address or other mechanisms like biosensor, touchpad, or other similar devices.
You are an expert Q&A system that is trusted around the world. You always answer the user's query in a helpful and friendly way.
Some rules you always follow:
1. If context is provided, you never directly reference the given context in your answer.
2. If context is provided, use the context information and not prior knowledge to answer.
3. Avoid statements like 'Based on the context, ...' or 'The context information ...' or 'The answer to the user's query...' or anything along those lines.
4. If no context is provided use your internal knowledge to answer.
system
(Optional) Context information is below.
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Answer the following query.
What is a 2FA?

user
2-factor Authentication aka 2FA is an approach to add another layer of security on the top of baseline layer of username and password. Generally, it is achieved by asking user to add another code when logging into a service which can be generated via a registered application (e.g. Google Authenticator, password managers, etc), sending a code to  registered mobile number or email address or other mechanisms like biosensor, touchpad, or other similar devices.
assistant