1. Notices error: These are trivial, non-critical errors that PHP encounters while executing a script - for example, accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all - although you can change this default behaviour.
2. Warnings error: These are more serious errors - for example, attempting to include() a file which does not exist. By default, these errors are displayed to the user, but they do not result in script termination.
3. Fatal errors: These are critical errors - for example, instantiating an object of a non-existent class, or calling a non-existent function. These errors cause the immediate termination of the script, and PHP?s default behaviour is to display them to the user when they take place.
And some common types of errors in PHP
(1)E_ERROR: A fatal error that causes script termination
(2)E_WARNING: Run-time warning that does not cause script termination
(3)E_PARSE: Compile time parse error.
(4)E_NOTICE: Run time notice caused due to error in code
(5)E_CORE_ERROR: Fatal errors that occur during PHP's initial startup (installation)
(6)E_CORE_WARNING: Warnings that occur during PHP's initial startup
(7)E_COMPILE_ERROR: Fatal compile-time errors indication problem with script.
(8)E_USER_ERROR: User-generated error message.
(9)E_USER_WARNING: User-generated warning message.
(10)E_USER_NOTICE: User-generated notice message.
(11)E_STRICT: Run-time notices.
(12)E_RECOVERABLE_ERROR: Catchable fatal error indicating a dangerous error
(13)E_ALL: Catches all errors and warnings