What do Java programs utilize to provide various functionalities?

Java programs utilize library packages to provide various functionalities, which is essential for modular programming and code reuse. Library packages in Java, also known as Java libraries or APIs (Application Programming Interfaces), consist of pre-written classes and methods that developers can call upon to perform common tasks. This modular approach allows programmers to avoid rewriting code for frequently used functionalities, such as data manipulation, input/output operations, and graphical user interface components.

Using library packages promotes efficient programming practices as developers can focus on application logic rather than the implementation details of the functionalities provided by these libraries. Packages like java.util for data structures and java.io for input and output operations are examples of how Java leverages these libraries to simplify the coding process and enhance productivity.

In contrast, while built-in functions are helpful, they do not encompass the full range of functionalities that library packages offer. World Wide Web protocols and operating system commands are not directly associated with Java programming itself but relate to broader contexts like networking and system interaction, respectively. Thus, the most accurate representation of how Java achieves functionality lies in its use of library packages.