In this chapter, we're going to learn about the use of the data package in Ext JS. Also, we will talk about Ajax, Data Models, Data Stores, and the available readers and writers that we can use in order to store our data locally.

The data package is what will let us load and save data in our code or application(s). It's important to have a solid understanding of the data package so we can link or bind data into Ext JS components. The data package contains multiple classes to handle data, but there are some main classes which will be used almost always. Take a look at the following figure:

Ext JS creates an abstract layer with a lot of classes and configurations; the idea is to use these classes when dealing with information. All the widgets and components that show information use the data package to manipulate and present the data easily.