Explaining Two-Factor Authentication for extra online security

Two-factor authentication can increase the security of your online activities. This video explains phone-based two-factor authentication, with a demonstration of how to enable it on Twitter.  

Many major web service providers now offer phone-based two-factor authentication under a variety of different names. The video has some useful links for these in its description on youtube.

Little Guide to Two Factor Authentification (video)

Stepping up to multi-factor authentication

New guidance on implementing MFA to better secure online services from the National Cyber Security Centre.

Find out how to turn on 2-Step Verification

How to setup Google 2-Step Verification  (video):-

Use 2-Step Verification without your phone (video):-

For the tech savvy, 2 Factor Authentication without a phone, using Keepass or Safe In Cloud (password managers) to generate TOTP (Time-based One-Time Password or Passcode - 6-digit code for 30 seconds) codes (shown in the useful video):-