Answer
Fixed and sticky positioning use different containing behavior. • A fixed box is normally positioned relative to the viewport and stays there while scrolling. • A sticky box behaves relatively until a scroll threshold is reached. • Sticky positioning needs an inset and is limited by its scroll container.
💡 Simple Example
.toolbar { position: sticky; top: 0; }
.help { position: fixed; right: 1rem; bottom: 1rem; }
⚡ Quick Revision
Fixed stays viewport-positioned; sticky sticks only within its scrolling limits.