Full Stack Web Development involves developing both the front-end and back-end of a web application. The front-end is built using technologies like HTML5, CSS3, JavaScript, jQuery, and Bootstrap, while the back-end uses PHP, MySQL, APIs, and server-side logic. A Full Stack Developer can build, test, deploy, and maintain complete web applications.

Front-end development focuses on the user interface and user experience using HTML, CSS, JavaScript, and Bootstrap. Back-end development handles server-side programming, databases, authentication, and business logic using PHP, MySQL, and APIs. Both work together to create a fully functional web application.

Responsive Web Design ensures that a website automatically adjusts to different screen sizes such as desktops, tablets, and smartphones. It improves user experience, mobile usability, SEO rankings, and accessibility while reducing the need for separate mobile websites.

PHP is a server-side scripting language used to create dynamic websites and web applications. It communicates with MySQL databases to store, retrieve, update, and delete information. Together, PHP and MySQL are widely used for login systems, e-commerce websites, content management systems, and business applications.

An API (Application Programming Interface) allows different software applications to communicate with each other. APIs are used to integrate payment gateways, maps, authentication services, social media logins, weather data, and third-party services into web applications.

Git is a version control system used to track code changes and collaborate with other developers. GitHub is a cloud-based platform that hosts Git repositories, making it easy to manage projects, review code, collaborate with teams, and maintain backup versions of applications.

Website performance can be improved by optimizing images, minimizing CSS and JavaScript files, enabling browser caching, reducing HTTP requests, using responsive images, compressing files, optimizing database queries, and choosing reliable web hosting.

I follow secure coding practices such as validating user input, using prepared SQL statements to prevent SQL Injection, sanitizing data to prevent XSS attacks, implementing authentication and authorization, hashing passwords, keeping software updated, and using HTTPS for secure communication.