What is IxD design?
Interaction Design (IxD) is the design of interactive products and services in which a designer's focus goes beyond the item in development to include the way users will interact with it. Thus, close scrutiny of users' needs, limitations and contexts, etc.
What is IA in UX?
IA is a blueprint of the design structure which can be generated into wireframes and sitemaps of the project. UX designers use them as the basic materials so that they could plan navigation system. UX design means much more than content structuring.