Information architecture (IA) is the structural design of shared information environments; the art and science of organizing and labelling websites, intranets, online communities and software to support usability and findability; and an emerging community of practice focused on bringing principles of design, architecture and information science to the digital landscape.^[1] Typically, it involves a model or concept of information that is used and applied to activities which require explicit details of complex information systems. These activities include library systems and database development.

Information architecture has somewhat different meanings in different branches of information systems or information technology:

1. The structural design of shared information environments.^[2]: 4
2. The art and science of organizing and labeling web sites, intranets, online communities, and software to support findability and usability.^[1][3]
3. An emerging community of practice focused on bringing principles of design and architecture to the digital landscape.^{[2]: 4 [4]}
4. The combination of organization, labeling, search and navigation systems within websites and intranets.^[2]: 4
5. Extracting required parameters/data of Engineering Designs in the process of creating a knowledge-base linking different systems and standards.
6. A blueprint and navigational aid to the content of information-rich systems.^[5]
7. A subset of data architecture where usable data (a.k.a. information) is constructed in and designed or arranged in a fashion most useful or empirically holistic to the users of this data.
8. The practice of organizing the information / content / functionality of a web site so that it presents the best user experience it can, with information and services being easily usable and findable (as applied to web design and development).^[6]
9. The conceptual framework surrounding information, providing context, awareness of location and sustainable structure.

The difficulty in establishing a common definition for "information architecture" arises partly from the term's existence in multiple fields. In the field of systems design, for example, information architecture is a component of enterprise architecture that deals with the information component when describing the structure of an enterprise.

While the definition of information architecture is relatively well-established in the field of systems design, it is much more debatable within the context of online information (i.e., websites). Andrew Dillon refers to the latter as the "big IA–little IA debate".^[7] In the little IA view, information architecture is essentially the application of information science to web design which considers, for example, issues of classification and information retrieval. In the big IA view, information architecture involves more than just the organization of a website; it also factors in user experience, thereby considering usability issues of information design.

• Richard Saul Wurman, credited with coining the term information architecture in relation to the design of information
• Peter Morville, president of Semantic Studios and co-author of Information Architecture for the World Wide Web (1998, 2002, 2006, 2015)
• Louis Rosenfeld, founder of Rosenfeld Media and co-author of Information Architecture for the World Wide Web (1998, 2002, 2006, 2015)
• Jesse James Garrett, co-founder of Adaptive Path and author of The Elements of User Experience (2002)
• Christina Wodtke, author of Information Architecture: Blueprints for the Web (2003)

• Wurman, Richard Saul (1997). Information Architects (1st ed.). Graphis Inc. ISBN 1-888-00138-0.
• Morville, Peter; Rosenfeld, Louis (2007). Information architecture for the World Wide Web (3rd ed.). Sebastopol, CA: O'Reilly & Associates. ISBN 978-0-596-52734-1. information architecture.
• Wodtke, Christina (2009). Information Architecture - Blueprints for the Web (2nd ed.). New Riders. ISBN 978-0-321-60080-6.
• Resmini, Andrea; Rosati, Luca (2011). Pervasive Information Architecture - Designing Cross-channel User Experiences (1st ed.). Morgan Kaufmann. ISBN 978-0-123-82094-5.
• Van Dijck, Peter (August 1, 2003). Information Architecture for Designers: Structuring Websites for Business Success. Rotovision. ISBN 9782880467319.

• Sue Batley (January 2007). Information Architecture for Information Professionals. Woodhead Publishing. ISBN 978-1-84334-233-5.
• Wei Ding; Xia Lin (15 May 2009). Information Architecture: The Design and Integration of Information Spaces. Morgan & Claypool. ISBN 978-1-59829-959-5.
• Earl Morrogh (2003). Information Architecture: An Emerging 21st Century Profession. Prentice Hall. ISBN 9780130967466.
• Alan Gilchrist; Barry Mahon (2004). Information Architecture: Designing Information Environments for Purpose. Facet. ISBN 9781856044875.