The explanation of all glitters is not gold

The common idiomatic expression, "all that glitters is not gold," means that some things that are "glittery" - things often considered attractive or desirable - aren't necessarily good

Explanation: - all that glitters is not gold said to mean that someone or something may not be as good or as valuable as they first appear

All that glitters is not gold and it's a good idea to delay finalizing any important agreements, otherwise you may jeopardize a valuable relationship.

all that glitters is not gold

reasons

not all you see, are actually what is good

some might seems good but they are not