PHP is primarily a Web-side server programming language, in other words, the server interprets the PHP code and generates code that can be read by a software application. More often, the code generated is HTML so that it can be read by a browser, but it can also be used for other languages or formats, such as WML, GIF, PDF, SVG, etc.
PHP was created to enable the development of dynamic applications, most often used for the Web. PHP can be installed on all the most commonly marketed Web servers; the most widespread are IIS and Apache. This pairing enables the recovery of information from a database, a file system (containing files in a tree structure) or simply data sent by a browser prior to being read or stored for another use.
It's a flexible, slightly unusual language that is easy to learn by a beginner. But due to these very reasons it can also cause security vulnerabilities to rapidly occur in applications.
PHP came into use with the development of Web forms that are accessible by a database. Database access is easy once the corresponding modules are installed on the server. The most obvious strength of PHP is that it has become over time an essential solution for hosting.
Open, free, simple to use and install, PHP, like all network languages, requires a strong understanding of the underlying mechanisms and knowledge of potential security problems.
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