"One of the secrets to being a super effective JavaScript developer is to truly understand the semantics of the language," writes developer Tim Caswell. That's why he's created a series of JavaScript lessons based on diagrams, each one illustrating a piece of example code. Caswell's lessons aren't geared towards new programmers. Those with no experience would be better served looking towards an introductory book on programming (or at least this tutorial) to learn the terminology and basic concepts. However, those wanting a deeper understanding of the JavaScript language will be well served by Caswell's tutorials. "My hope is that this helps those of us that are visual learners to get a better grasp of JavaScript semantics," he writes.