The following are official DSIA definitions that disambiguate the term “information architecture.”
Information Architecture (Practice)
Information architecture (IA) is a practice of “organizing and relating information in a way that simplifies how people navigate and use content presented in application user interfaces.” 
Information architecture analysis and documentation add structural coherence to strategy and have a material impact in the design and implementation of human-computer interaction. While IA methods can be applied in other professional domains, the practice is predominately applied to the Web.
It’s important to note the Information Architecture Institute expresses a broader description of IA practice that does not limit it to the domain of technology. They define information architecture as a “practice of deciding how to arrange the parts of something to be understandable.” The IA Institute advises that the practice of information architecture involves “facilitating the people and organizations … to consider their structures and language thoughtfully.”
Information Architecture (Work Product)
The abstract and physical constructs derived from IA analysis are often called the “information architecture.” An information architecture consists of structural definitions (see List 1.0) that are necessary to articulate the concept and content constraints for a target system. These definitions are generally consumed as diagrams that are representative models of the environment in question.
Information architecture modeling is agnostic to the modality of its subject. As long as an object can be observed, its information architecture can be studied and represented to suggest an optimal relational structure of interdependent constituents and their role in supporting a targeted set of behaviors or explicit objectives.
List 1.0 – DSIA structural definitions for documenting information architecture
- Base model
- Business model
- Concept model
- Content model
- Controlled vocabulary
- Domain model
- Entity model
- Flow model
- Information model
- Channel mapping
- Mental model