I'm reading through this site regarding REST - http://rest.elkstein.org. I'm reading this in order help me have a stronger understanding before I diver further into frameworks such as angular and others. Additionally I'm looking into WP-API - https://github.com/WP-API/WP-API.

Most my experience is in graphic design and front-end development excluding JS. So that's where I'm coming from. Obviously I need to learn more JS but I'm curious if there is other information I should research in order to better grasp the latest JS frameworks and trends. I'm occasionally coming across terms I don't have a strong understanding of such as stateless.