A CSS gradient is a smooth transition between two or more colors, generated directly by the browser. Unlike image-based gradients, CSS gradients are rendered in real-time, making them resolution-independent and highly performant. They're defined using the background or background-image property and can be linear, radial, or conic.

There are three main types: Linear Gradients (colors transition along a straight line), Radial Gradients (colors radiate from a central point outward in a circular or elliptical shape), and Conic Gradients (colors rotate around a center point in a cone-like pattern). Each type supports multiple color stops and customizable angles, positions, and sizes.

You can use as many color stops as you need — there's no practical limit. Each color stop defines a color and an optional position (in percentage or length units). Browsers automatically interpolate colors between stops, creating smooth transitions. Common gradients use 2-5 stops for clean, professional results.

Yes! Linear and radial gradients have near-universal support (97%+ of global browsers). Conic gradients are supported in all modern browsers including Chrome, Firefox, Safari, and Edge. For very old browsers like IE11, consider providing a solid fallback color before the gradient declaration.

While CSS gradients themselves aren't directly animatable with transition, you can animate gradient-related properties using @keyframes with background-position (by increasing background-size and shifting position), or by using CSS custom properties with @property for smooth color interpolation in modern browsers.

A repeating-linear-gradient repeats the color stop pattern infinitely across the gradient area. While a regular linear gradient transitions from the first color to the last and stops, the repeating version tiles the pattern. This is great for creating striped patterns, progress bars, or decorative backgrounds.