When working in Cloud based environments, you won't really do much in the way of routing. Not a whole lot, anyway. Just understanding that a router is will you understand some keywords and concepts when you eventually work with advanced networking concepts in AWS (or any other Cloud environment.)
A router allows systems in one network to talk to systems in other networks. Because switches operate on the local network, they don't know where to "find" systems on other networks. This is what a router is for.
Without routers the public Internet as we know it today would simpy not exist.