A script language and interpreter, similar to JavaScript and Microsoft's VBScript, that is freely available and used primarily on Linux Web servers. PHP is a cross-platform alternative to Microsoft's Active Server Page (ASP) technology.

An HTML-embedded scripting language allowing web developers to create dynamic, database-driven websites. Much of PHP3.0 is a combination of Perl, Java, and C concepts.

The Zend Engine-powered PHP  4 is an improvement of  PHP 3. Its optimized performance results from the redesign of the scripting engine to a "compile-then-execute" paradigm, whilst PHP 3 adopts the  "execute-while parsing" model.

PHP 5  build on the foundation laid by PHP 4. It has improved Object Oriented Programming capabilites.

PDO is an acronym for PHP Data Objects. PDO is a lean, consistent way to access databases. PDO is not an abstraction layer like PearDB. PDO is a more like a data access layer which uses a unified API (Application Programming Interface)

A function that returns a string formatted according to the given format string using the given integer timestamp or the current time if no timestamp is given. 

PHP Developer Certificate by W3Schools

PHP framework is a software framework that is designed to support the development of dynamic websites, web applications, web services and web resources. The framework aims to alleviate the overhead associated with common activities performed in web development. It provide libraries for database access, templating frameworks and session management, and they often promote code reuse.

  A PHP function that allows the sending emails directly from a script. It returns TRUE if the email was successfully accepted for delivery, otherwise it returns FALSE.

A fully featured email transfer class for PHP.

A free software tool written in PHP, intended to handle the administration of MySQL over the World Wide Web. Itsupports a wide range of operations with MySQL.

Phusion Passenger is a free web server and application server with support for Ruby, Python and Node.js. It is designed to integrate into the Apache HTTP Server or the nginx web server, but also has a mode for running standalone without an external web server. Phusion Passenger supports Unix-like operating systems, and is available as a gem package, as a tarball, or as native Linux packages.

In a Citrix XenServer, a physical block device is a connector object that represents the interface between a physical host and an attached storage repository (SR). 

The protection of personnel, hardware, programs, networks, and data from physical circumstances and events that could cause serious losses or damage to an enterprise, agency, or institution. 

A combination of hardware and software dedicated to the short and long term storage, retrieval, management, distribution and presentation of images. The biggest consumers of PACS are hospitals. 

Apache Pig is a platform for analyzing large data sets that consists of a high-level language for expressing data analysis programs, coupled with infrastructure for evaluating these programs. The salient property of Pig programs is that their structure is amenable to substantial parallelization, which in turns enables them to handle very large data sets.