Transport Layer Security Inspection (TLSI) is the process through which enterprises can inspect encrypted traffic with the help of a dedicated product such as a proxy device, a firewall, intrusion detection or prevention systems (IDS/IPS) that can decrypt and re-encrypt traffic encrypted with TLS. Some enterprises use this technique for monitoring potential threats such as data exfiltration, active command and control (C2) communication channels, or malware delivery via encrypted traffic, this will also introduce risks.
Source: https://www.bleepingcomputer.com/news/security/nsa-publishes-advisory-addressing-encrypted-traffic-inspection-risks/