What is the significance of the error "Allowed memory size exhausted" in PHP?

The error "Allowed memory size exhausted" in PHP occurs when a script tries to allocate more memory than the limit set in the php.ini configuration file. This can happen when a script is trying to process a large amount of data or when there is a memory leak in the code. To solve this issue, you can increase the memory limit in the php.ini file or optimize your code to use memory more efficiently.

// Increase memory limit
ini_set('memory_limit', '256M');