What is mod_php?

mod_php is an Apache module that allows PHP code to be executed directly by the Apache web server. This means that when a client (such as a web browser) requests a PHP page, the server can execute the PHP code and return the resulting HTML to the client, without the need for a separate PHP interpreter. This can improve the performance and scalability of PHP applications, as it reduces the overhead of starting and managing separate PHP processes. However, it also means that all PHP code runs with the same permissions as the web server, which can be a security concern.

mod_php is the most widely used method of running PHP on a web server, but it has been largely replaced by other options such as PHP-FPM (FastCGI Process Manager) and mod_proxy_fcgi which is a more modern and secure way of executing PHP code on a web server.

Mod_php is considered as a less secure option to run PHP code because it runs all PHP code with the same permissions as the web server, which can be a security concern. Additionally, if a vulnerability is discovered in the PHP code, an attacker could potentially gain access to the entire web server and all of its data.

In summary, mod_php is an Apache module that allows PHP code to be executed directly by the Apache web server, it is widely used but it is less secure, less efficient and less scalable than other alternatives like PHP-FPM or mod_proxy_fcgi.