Shapes serve as image masks (circular or blob-shaped photo crops), section dividers (wave or diagonal edges), background decoration (floating geometric elements), and content containers (non-rectangular cards). They break the default rectangular nature of web elements.
Clip-path creates custom polygon and shape outlines, border-radius handles circles and rounded forms, and SVG provides limitless organic shapes. CSS shapes (shape-outside) allows text to wrap around non-rectangular forms, while mask-image enables complex masking effects.