It's either an Ethernet port light or one of those cryptic things from AliExpress without a manual.

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There was once someone who knew.

It did have a useful purpose at one point for expert users, technicians, and engineers.

A large group came along chanting "What does it mean?" louder and louder until it was a thunderous war-cry.

The one who knew was trying to shout the answer but he was whispering in a tornado.

Then, someone else said loudly: "I don't understand. Let's just get rid of it."

Most everyone said: "Yeah! It's useless!"

No one listened and now that that understanding is lost like the Antikythera mechanism and Damascus steel to the sands of time.