HTML (HyperText Markup Language): The backbone of any web page, used to structure content.

CSS (Cascading Style Sheets): Used for styling HTML elements, controlling layout, and design.

JavaScript: Essential for adding interactivity and dynamic functionality to web pages. It's also used for client-side scripting.

Version Control/Git: Understanding version control systems like Git is crucial for collaborative development and managing code changes.

Responsive Design: Knowledge of techniques and frameworks like Bootstrap for ensuring web applications are optimized for various devices and screen sizes.

Web Performance Optimization: Understanding techniques to improve website speed and performance, such as image optimization, minification, and caching.

Backend Languages/Frameworks: Depending on the project, you might need to know server-side languages like Python (with frameworks like Django or Flask), JavaScript (Node.js), Ruby (Ruby on Rails), PHP, etc.

Databases and SQL: Understanding database management systems (e.g., MySQL, PostgreSQL, MongoDB) and SQL for data storage and retrieval.