In the context of programming languages, what does portability refer to?

Portability in programming languages refers to the ability of software to run on multiple platforms without requiring substantial modification. This characteristic is pivotal because it allows developers to write code that can function across different operating systems, hardware architectures, or environments. When a programming language is designed with portability in mind, it often employs standardized syntax and semantics, which facilitates the transition of applications from one system to another.

For instance, languages such as Java are specifically known for their portability due to the Java Virtual Machine (JVM), which enables Java programs to run on any device that has a compatible JVM installed, regardless of the underlying hardware or operating system. This universality reduces the need for developers to rewrite code for different environments, thereby enhancing development efficiency and broadening the software's usability.

The other choices, while important aspects of programming, do not capture the essence of portability. Hiding errors automatically relates more to error handling and debugging. The speed of execution is concerned with performance, which can vary across different systems. Lastly, the efficiency of resource usage pertains to how well the program utilizes system resources, which is more about optimization rather than the ability to operate across various platforms.