Pretexting is when a social engineer obtains information from someone through false identities and lies.
In many cases, the social engineer may pretend to be a co-worker, boss, government agent, police officer, or even a friend!
They use information garnered from a victim’s social media accounts to form a profile of their victim, and use that information in conversation to gain the victim's trust.
Once they have that trust, they will ask questions whose answers can be used to confirm a victim’s identity, and then use that information to gain access to more sensitive information.
For instance, knowing your birthday may allow a social engineer to take control of your cell phone account by calling your cell provider's support line.