Each identity management, authentication techniques, single sign-on, and access control monitoring, are involved with security and data access.
Authentication techniques are means of accessing sensitive data and can be something you have, something you know, or something you are.
Something you have could be a key or phone. Something you are would be biometric, and something you know would be a PIN or password/passphrase
A SSO (single sign on) involves complex tokens used in a way that only requires the user to sign on a single time to access a site or resource, a social media profile like facebook would be a good example.