Document difference between error and exception

Affected page

https://www.php.net/manual/en/reserved.exceptions.php

Current issue

From https://www.php.net/manual/en/class.error.php and https://www.php.net/manual/en/class.exception.php, it seems that Error is thrown by PHP and Exception is for userland code:

Exception is the base class for all user exceptions.

Error is the base class for all internal PHP errors.

This is not accurate and not complete.

Suggested improvement

PHP also throws Exception subclasses. But the semantic meaning is different, apparently.

https://github.com/php/policies/blob/main/coding-standards-and-naming.rst#throwables

The Error hierarchy MUST NOT be used for errors that are expected to be thrown (and caught) during normal operation of a PHP program.

As an example, a parsing function that is expected to be used with untrusted input must not throw an Error if the input is malformed. Similarly a function that interacts with the network must not throw an Error if the network operation fails. Any Error that is thrown should usually result in a reasonably obvious fix in the PHP program.

Tim also said that Error is not supposed to be caught, only Exception is.

Additional context (optional)

No response

Start with the affected page, reserved.exceptions.php, and compare its wording with class.error.php and class.exception.php. Read the linked PHP throwable coding standards for the intended distinction, then revise the explanation so it accurately describes when Error and Exception subclasses are used and verify the documentation links and examples.