Nintex Forms provide an interface between a user and persistent data. The form surface provides the ability to provide data entry structures such as list boxes (providing a set of choices), check boxes (providing yes and no settings), validation of data entry, and the ability to send the data to persistent storage such as a database. Nintex Forms are designed to work with Microsoft SharePoint lists and Nintex Workflow.
One of the most powerful features in SharePoint that doesn’t get used nearly as often as it should is workflow.
As a developer, all we care about is programming language, patterns, UI & data storage. However users do not care how the hell it is implemented, all they care is that does it useful or solves the given problem.
There is no point in blaming each other, we have to understand the each other to be successful.
Dependency Injection allows us to inject objects into a class, instead of constructing them internally. Unity is a dependency injection container that we can use for constructor, property, and method call injections.
You can get good idea about dependency injection by reading this post.
In this article, you can learn how to use Unity with WebAPI.