Answer Description

Shoulder surfing is a common tactic to gain information by standing near a person as they talk on the phone, fill out a form, or type in their password.

Wikipedia

In computer security, shoulder surfing is a type of social engineering technique used to obtain information such as personal identification numbers (PINs), passwords and other confidential data by looking over the victim's shoulder. Unauthorized users watch the keystrokes inputted on a device or listen to sensitive information being spoken, which is also known as eavesdropping.