IMO, signs and omens are the same thing. They can be anything that jumps out at us, seemingly from nowhere, are crystal clear, and point at a particular path, direction, task, idea. Heed your signs, good or bad. Follow your instincts as much as you can. The universe gives us warning signs as well as doors to our next steps.
I've recently realized curiosity about the unknown, may literally open doors that should not be opened. An omen warned me to leave that door shut! I'm going to heed the sign. Your reply is a crystal clear omen I needed to understand what took place. Thank you for the great explanation