Information architecture is a conceptual organisation scheme for information on a website.
The information architecture for a website defines items such as
- how different types of information relate to each other
- what sort of information to provide on each web page
- how to label information so it makes sense to users
- what navigation scheme will help users find information easily
- what search features to include
An ideal information architecture matches users' mental models about how ideas, tasks and features "fit together" and makes a website intuitive to use.