Information architecture (IA) is the art and science of organizing and structuring information in a way that optimizes findability and understanding. It involves developing navigation systems, labeling schemes, and content organization to help users easily find desired information. Key aspects of IA include navigation and labeling systems, content organization, and information storage and retrieval structures. Proper IA helps users intuitively understand a website's information hierarchy and structure, improving the user experience and supporting better search engine optimization.