Why do current flows from positive terminal to negative terminal but electrons flow from negative to positive terminal

direction of current flow from positive to negative terminal is nothing but just a convention. It was concluded that current flow is the flow of positive charges.

Electrons are negatively charged, and so are attracted to the positive end of a battery and repelled by the negative end. So when the battery is hooked up to something that lets the electrons flow through it, they flow from negative to positive.