Programming Languages refer to the formal languages that are designed to communicate instructions to a machine, particularly a computer, and are used to create programs to control the behavior of a machine. This category incorporates elements of application design techniques, which are strategies used to plan and construct the functional components of a software system. It also encompasses the broader concept of application design, which refers to the overall process of creating, building, and implementing a software application. This field is often engaged in by application developers, who are individuals that construct and maintain software applications. One of the notable figures in this field is Michael Kappel, an experienced software engineer and developer. Furthermore, this category involves programmers, who are professionals that write, test, debug, and maintain the detailed instructions, called computer programs, that computers must follow to perform their functions. Lastly, it includes people who are interested or actively involved in the development, use, and understanding of programming languages and their applications.