What is it?
Information Architecture (IA) is a practice focusing on organizing, structuring, and labeling content in an effective way. The structure you present the content, the flow and navigation in the product to the user is directly related to the success of your product.
How can I use it?
First of all, you need to know your user. Also review your competitors and your scope. In this process, you will have an idea about the content of your product. Then convert the content into a user-friendly hierarchical structure with card sorting and similar methods. By testing and reviewing this structure/map you have created, you will reach your information architecture. The outputs of the information architecture practice can be in different forms such as sitemap and wireframe.
When can I use it?
After you have the required data about your users and their behaviors, your competitors and your scope, you can focus on information architecture. It will be one of your main guide books in later stages such as wireframing.