PHP and JavaScript are both powerful scripting languages, but they serve distinct purposes in web development. PHP, launched in 1995, primarily functions as a back-end language, widely used for creating dynamic websites. Its performance and security are well-regarded, making it a go-to for scalable web applications. PHP's simplicity and extensive library support make it a popular choice for developers working with CMS platforms like WordPress, Drupal, and Joomla. Moreover, it integrates seamlessly with databases such as MySQL and PostgreSQL, offering flexibility and reliability for server-side development.

On the other hand, JavaScript, also released in 1995, is predominantly used for front-end development, creating interactive and user-friendly websites. One of JavaScript's strengths is its human-readable source code, making it accessible for developers. JavaScript excels in client-side applications, reducing the load on servers. It supports modern web technologies like HTML, XML, and Ajax and integrates well with frameworks like Angular, React, and Node.js. While PHP dominates server-side programming, JavaScript's versatility in both front-end and server-side environments has made it an essential tool in modern web development.