What Searle was saying

A computer program is like the person in the room.

The program receives inputs (symbols). It applies rules (its code). It produces outputs (more symbols). At no point does it understand what any of those symbols mean.

The program might pass the Turing Test. It might fool every judge who tries it. Searle says: so what?

The person in the room fooled everyone outside, and understood nothing.

Searle called this the line between syntax and semantics. Syntax is the shape and arrangement of symbols. Semantics is their meaning. Computers, he argued, can only manipulate syntax. True meaning? That's something else entirely.