What is PHP?
PHP is an open-source server-side scripting language that is commonly used for web applications.
What is Open Source Software?
Software in which the source codes are freely used, modified, and shared by anyone is called Open Source Software. These can also be distributed under licenses that adhere to the open source definition.
What is the difference between include(), include_once(), and require_once()?
The include() statement includes and evaluates a specified line i.e. it will include a file based on the given path. require() does the same thing except upon failure, it will generate a fatal error and halt the script whereas include() will just give a warning and allow the script to continue. require_once() will check if the file already has been included and if so, it will not include the file again.
Differences between GET, POST, and REQUEST methods
GET and POST are used to send the information from client browser to the web server. In case of GET, the information is sent via GET method in name/value pair and is URL encoded. The default GET has a limit of 512 characters. The POST method transfers the information via HTTP Headers. The POST method does not have any restriction in data size to be sent. POST is used for sending data securely and ASCII and binary type’s data. The $_REQUEST contains the content of both $_GET, $_POST and $_COOKIE.