ELI5 Presidents vs Prime Ministers - why do some countries have both?

Why do some countries have Presidents, some have Prime Ministers, and some countries have both? What is the difference? What about France, where there’s both a president and a prime minister. Why is it that in some places the President is more powerful but in others like Germany the Prime Minister is more powerful? ... 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: lawstuden2, lancashire_lad, feb914, winstonl, psyk60 and chickentrousers 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]