Flow control is a mechanism that allows a network device to regulate the amount of traffic it can receive or send. Flow control can help prevent congestion and buffer overflow by sending pause frames or signals to the sender when the receiver's buffer is full or nearly full. Flow control can cause traffic to pause, allowing the switches to drain buffers and resume normal operation. Speed is a parameter that determines the data transfer rate of a network link. 802.1Q is a standard for VLAN (Virtual Local Area Network) tagging, which allows multiple logical networks to share the same physical infrastructure. Duplex is a mode of communication that determines how data is transmitted and received on a link. Full duplex allows simultaneous transmission and reception, while half duplex allows only one direction at a time.

Explanation
Shoulder surfing is the social engineering attack where an attacker watches a user log in to a corporate system and writes down the user's log-in credentials. Social engineering is a type of attack that exploits human psychology and behavior to manipulate or trick people into revealing sensitive information or performing malicious actions. Shoulder surfing is a form of social engineering that involves observing or eavesdropping on someone's screen, keyboard, or paper documents to obtain confidential information such as passwords, PINs, or credit card numbers. Shoulder surfing can be done in person or remotely using cameras or other devices. Shoulder surfing can be prevented by using privacy filters, locking screens, shielding keyboards, or being aware of one's surroundings. References: [CompTIA Network+ Certification Exam Objectives], What Is Shoulder Surfing? | Definition & Examples | Forcepoint