What are extensions in php?

Php extensions are nothing but libraries that can be used to interact with different kinds of applications.

For example - php_soap is one of the php extensions and it is used to work with web services. You can create soap requests and get the response from the server.

Below is the list of important extensions in php that we use.

• php_soap
• php_mysql
• php_mysqli
• php_pdo_mysql
• php_zip
• php_sockets
• php_ldap

To work with different kinds of databases php has got different extensions like php_mysql, php_oci8 etc.

You can enable or disable the php extensions in php.ini file

For example - 

To enable soap extension you can use below statement in php.ini

extension=php_soap.dll

To disable soap extension you have to prefix the statement with semicolon in php.ini

;extension=php_soap.dll