Full packet capture provides the complete recording of all the packets that are transmitted over the network.
This data is essential for in-depth analysis during an investigation, as it allows investigators to reconstruct the session, observe the content of the traffic, and determine if data exfiltration has occurred.
Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) study materials would typically cover the importance of full packet capture in network forensics and incident response.

Encryption is challenging to security monitoring because it can be used by threat actors as a method of evasion and obfuscation. Encryption can prevent security devices from inspecting the content or payload of the network traffic, making it difficult to detect malicious activity or signatures. Encryption can also hide the source and destination of the traffic, making it hard to trace the origin or destination of the attack. References:
https://learningnetworkstore.cisco.com/on-demand-e-learning/understanding-cisco-cybersecurity-operations- fundamentals-cbrops-v1-0/CSCU-LP-CBROPS-V1-028093.html (Module 4, Lesson 4.1.1)