what is the difference between PHP5 and PHP7?

Question

By default centos and epel repo have php5 as the default version. It is an outdated version. Some other repos help me to install php7. What is the difference between php5 and php7?

Answer 1

The performance of PHP 7 and PHP 5 is a major difference. you have written a PHP code in PHP 5, if you run the same code in both versions, the performance of PHP 7 will be significantly higher than PHP 5.  PHP 5 uses Zend II but PHP 7 uses a brand new model of engine called PHP-NG or Next Generation