Web development refers to the process of building and maintaining websites. It involves a variety of tasks, including web design, coding, content creation, and server configuration, aimed at creating a functional and visually appealing online presence.

The key components of web development include front-end development, which focuses on the user interface and experience, and back-end development, which involves server-side programming and database management. Additionally, web development may involve aspects such as web security, SEO (search engine optimization), and content management systems (CMS).

Common programming languages used in web development include HTML (Hypertext Markup Language) for creating web pages, CSS (Cascading Style Sheets) for styling and layout, and JavaScript for adding interactivity and dynamic content. Additionally, back-end development often involves languages like PHP, Python, Ruby, and Java.

Responsive web design is an approach to web development that ensures websites adapt and respond to different screen sizes and devices, such as desktop computers, laptops, tablets, and smartphones. This ensures optimal viewing and usability across various platforms and screen resolutions.

Front-end development involves building the visible parts of a website that users interact with, including the layout, design, and functionality. Back-end development, on the other hand, focuses on the server-side logic and database management that support the front-end functionality, handling tasks such as data processing, user authentication, and server communication.