ELI5 Port and Starboard - why not just left and right?

Why do ships use “port” and “starboard” instead of “left” and “right?” Where did the terms originate? What does “aft” mean and why is it different from the stern? Why do large ships have their anchors in the bow and not the stern or either port or starboard sides?  ... 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: jattopotamus, dbht14, commissaraj, quintus_horatius and proofbox 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: [email protected]