What is the difference between include and require in PHP?

Include and require are both PHP functions used to include and evaluate the specified file in the script. The main difference between the two is how they handle errors:

• Include: If the specified file is not found, include will only produce a warning message and continue executing the script.
• Require: If the specified file is not found, require will produce a fatal error and stop the script execution.

It is generally recommended to use require when you want to make sure that a certain file is included and properly loaded, as it prevents the script from continuing if the file is missing. On the other hand, include can be useful when you want to include optional files that are not critical for the script execution.