What distinguishes a runtime error from a syntax error?

A runtime error occurs when there is an issue during the execution of the program, meaning the code compiles without any issues, but then behaves unexpectedly when it is run. This can happen due to various reasons such as division by zero, accessing an element outside the bounds of an array, or insufficient memory. The key aspect of runtime errors is that they are detected after the code has been successfully compiled and while it is executing.

In contrast, syntax errors are problems with the way the code is written. They are typically detected during the compilation phase, and these errors prevent the code from compiling at all. Syntax errors can include misspelled keywords, missing parentheses, or incorrect punctuation, all of which need to be resolved before the program can run.

Understanding this difference is crucial for debugging programs effectively. While runtime errors highlight potential logical or operational issues within the program's flow, syntax errors point toward mistakes in the structure of the code that must be fixed beforehand.