What best describes a library in the context of programming?

A library in programming is fundamentally understood as a collection of pre-written code that developers can utilize to perform common tasks without having to write that code from scratch. This code can include functions, classes, procedures, and even configuration data, all designed to be reused in various applications.

The advantage of using a library is that it promotes code reuse, leading to more efficient development processes and reducing the likelihood of errors since the library's code is typically well-tested. By leveraging libraries, programmers can focus on the unique aspects of their applications instead of spending time on widely-used functionalities.

Other choices provide descriptions that do not capture the essence of what a library embodies. For example, while a library can include executable code, it is not merely a static file; it is a comprehensive collection of tools and functions. Visual designs for user interfaces pertain to user experience (UX) and design, distinctly separate from the concept of libraries, which focus on code functionality. Lastly, the mention of algorithms, such as those for sorting, does not align with the broader definitions and functionalities that a library encapsulates, which includes not only algorithms but a wide range of utilities and tools for developers.