What is the primary use of Java in web development?

Java's primary use in web development is indeed to enhance websites with small programs or applications. In the context of web development, Java can be utilized to create applets and web applications that run on the client side, enhancing the interactivity and functionality of web pages.

Java applets, though less common nowadays due to security concerns and the evolution of technology, were designed to provide interactive features that can run within a web browser. In addition, Java is heavily used on the server side through frameworks such as Spring and JavaServer Faces (JSF), which support the development of complex web applications. Its object-oriented nature, portability across different platforms, and robust security features make it an ideal choice for building components that can interact with web technologies effectively.

The other options, while relevant to some aspects of web development, do not encapsulate the primary role of Java. Crafting server-side databases involves different technologies such as SQL or database management systems; managing web traffic is primarily handled by web servers and load balancers; and designing user interfaces is usually done with HTML, CSS, and JavaScript, although Java can contribute to UI development via frameworks. However, in the broader scope of enhancing web applications, Java plays a crucial role.