CSS3
CSS3 (Cascading Style Sheets Level 3) is the latest major version of the CSS language used for describing the presentation and styling of web documents written in HTML or XML. It introduces advanced features like animations, transitions, gradients, flexbox, grid layouts, and responsive design capabilities, enabling developers to create visually rich and interactive user interfaces without relying heavily on JavaScript or images.
Developers should learn CSS3 to build modern, responsive, and accessible websites that work across various devices and screen sizes. It is essential for front-end web development, allowing precise control over layout, typography, colors, and animations, which enhances user experience and performance by reducing the need for external libraries or complex scripts.