How are failures in execution handled with include() and require() functions?

The include() and require() functions are used to include and evaluate the content of another PHP file in the current script. If the specified file is not found, the include() function generates a warning and continues script execution. On the other hand, if the specified file is not found, the require() function generates a fatal error and stops script execution. The choice between include() and require() depends on the specific requirements of your script. If the included file is essential for the script to run correctly, require() is preferred to ensure that any missing files are detected as fatal errors and prevent the script from running with incomplete dependencies.