Authentication: Verifying "who" the user or device is (e.g., via passwords, certificates).
Authorization: Controlling "what" a user or device can do once authenticated (e.g., read-only vs.
read/write permissions).
Combined for Security: Both are essential. Authentication alone doesn't control access levels, and authorization without verification is meaningless.

Most Vulnerable In Transit: Sensitive data (passwords, health information, etc.) is most susceptible to interception while being sent over a wireless network. Encryption is crucial at this stage.
Encryption at Rest and in Memory: While also important, these are often handled with different cryptographic techniques depending on the system.

Perception Layer: The foundation of an IoT system, it consists of sensors and actuators that:
Sense: Collect data about the environment or object being monitored.
Actuate: Potentially make changes based on commands (e.g., a smart valve opening/closing).
Transmit: Send gathered data to upper layers for processing.

Airtime utilization determines how many clients an AP can serve. Wider channels and high utilization reduce capacity. SSID names, DHCP timing, and cabling have minimal impact.