What are error.log, Notices, Warnings and Fatal messages¶

• A warning (PHP Warning) is a message saying “You are doing something wrong and it is very likely to cause errors in the future, so please fix it.”
• A notice (PHP Notice) is an advisory message meaning “You probably shouldn’t be doing what you’re doing, but I’ll let you do it anyway”

Both notices and warnings will not halt execution of your script, although I would encourage you to take them seriously and strive to have not even one notice in your apps.

A error (PHP Fatal error, for example) is a message saying “You are doing a very wrong and bad stuff. Execution of the script is halted.”