The first thing you need to know in order to become a web developer is what web development actually is. It’s a term that gets used very broadly, and one person’s definition of web development can be pretty different from the next.
Generally speaking, web development is working on the technical aspects of a website. A web designer is the person in charge of the visual design and layout of the website, and the web developer takes that design and vision from a static design to a fully working website that is online and available to the world.
It’s important to note that many web designers are also developers in that they build the websites they design. Also, occasionally, a self-identified web developer will also offer design services. The terms are not interchangeable, but they also aren’t mutually exclusive.