Imagine a messenger that uses TLS between your phone and its server. The server opens the message, stores a readable copy and sends it onward through another protected connection. People watching the network may not read the message, while the operator can access the copy it holds.

This is a hypothetical design, not a claim about every messenger or text-message system. To understand a real service, locate where content becomes readable and which parties hold the necessary keys. “Encrypted” alone does not answer that question.