What is Social engineering?

Social engineering is that get important security information from managers or user of network by deceiving them. the crimes use human psychological carelessness very well. We must be careful when we use computer or have important information. There are some ways ; Using a false name is the most common way and also taking a peek at the computer when you are typing your password or picking them up from trash can is often happen. How can we prevent them? putting the papers in the shredder and Do not accept the phone call from pay phone could avoid those happens.