Generally in programming, the terms error and exception are often used interchangeably. Within the Node environment, these two concepts are not identical. Errors and exceptions are different. Additionally, the definition of error and exception within Node does not necessarily align with similar definitions in other languages and development environments.
Conventionally, an error condition in a Node program is a non-fatal condition that should be caught and handled, seen most explicitly in the Error as first argument convention displayed by the typical Node callback pattern. An exception is a serious error (a system error) that a sane environment should not ignore or try to handle.
One comes across four common error contexts ...
