为什么它说错误层次结构不是来自php中的异常?

I am new to php world and learning from php.net and this paragraph wasted all my day. Can anyone tell what does this paragraph tells on that reference link (http://php.net/manual/en/language.errors.php7.php)?

As the Error hierarchy does not inherit from Exception, code that uses catch (Exception $e) { ... } blocks to handle uncaught exceptions in PHP 5 will find that these Errors are not caught by these blocks. Either a catch (Error $e) { ... } block or a set_exception_handler() handler is required.

It says that the error reporting mechanism has changed in PHP.

In PHP5 you used to catch exceptions and errors with the following code

catch (Exception $e) { ... } 

but now in PHP7 you need to use the following code in order to get all errors.

catch (Error $e) { ... }