Web application development refers to the creation of software applications that run on web servers and are accessible via the internet using a web browser. It involves the development of front-end and back-end components that work together to deliver dynamic web content and functionality. This may include technologies such as HTML, CSS, JavaScript, server-side scripting languages like PHP or Python, and databases like MySQL or MongoDB. Web application development can be used to create a wide range of applications, from simple informational websites to complex e-commerce platforms and enterprise-level systems.