ELI5 Schrödinger's Cat - is the cat both dead and alive and why does it matter in quantum mechanics?

Explain Schrödinger's Cat in simple terms. Why did Erwin Schrödinger propose this thought experiment in the first place? What was Schrödinger trying to argue against with his cat example? Which other scientist inspired Schrödinger to devise the cat?  ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: culturedgoat, flurb4, use-paragon, tenor1, hackey_sack, western_ground7478 and burnoutbrigheter6 To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: ELI5ThePodcast@gmail.com