Front-end development, also known as client-side development, is the practice of producing HTML documents, CSS style sheets, and JavaScript script code (Figure 1) for a website or Web Application - so a user can see and interact with them directly.
Back-end development, also known as server-side development, is the practice of producing complex websites using programming languages such as SQL, Java, PHP, or .NET (Figure 2) to provide features beyond front-end capabilities.