Web developers use a variety of programming languages to build websites and web applications. Some of the commonly used programming languages in web development include: HTML: HTML (Hypertext Markup Language) is the standard markup language used for creating the structure and content of web pages. CSS: CSS (Cascading Style Sheets) is used to style and format the appearance of HTML elements on a web page. JavaScript: JavaScript is a versatile programming language that enables interactivity and dynamic behavior on web pages. It is commonly used for client-side scripting. Python: Python is a high-level programming language that is often used for web development. It offers various frameworks like Django and Flask for building web applications. PHP: PHP (Hypertext Preprocessor) is a server-side scripting language that is widely used for web development. It is commonly used in conjunction with HTML to create dynamic web pages. Ruby: Ruby is a dynamic, object-oriented programming language that is often used with the Ruby on Rails framework for web development. Java: Java is a popular programming language that is used for a wide range of applications, including web development. It is commonly used with frameworks like Spring and JavaServer Pages (JSP). C#: C# (pronounced C sharp) is a programming language developed by Microsoft. It is commonly used with the ASP.NET framework for web development on the Microsoft platform. Go: Go, also known as Golang, is a programming language developed by Google. It is known for its simplicity and efficiency and is increasingly being used for web development. Swift: Swift is a programming language developed by Apple. While it is primarily used for iOS and macOS app development, it can also be used for server-side web development. These are just a few examples of the programming languages commonly used by web developers. The choice of programming language depends on various factors such as the project requirements, developer's familiarity, and the specific goals of the web application.