You may wonder why you would ever use the TI-Nspire Graphs application to graph and analyze two-variable data. Here are two reasons why you may choose to use the Graphs application over the Data & Statistics application:
Function graphing and analysis: Although the Data & Statistics application offers several tools to analyze graphed functions (for example, Graph Trace and Shade Under Function), the Graphs application offers several additional options not available in Data & Statistics. For example, the Graphs application enables you to translate and stretch graphs as well as add a function table, perform calculations, construct a locus, transfer measurements, and so on.
Geometry tools: The Graphs application allows you to add geometric objects including lines, segments, circles, tangents, and so on. For example, perhaps you want to add a tangent to a graph for the purpose of exploring the rate of change.
The Data & Statistics application also has several advantages over the Graphs application. You might even use Data & Statistics more than Graphs to graph a scatter plot. Why? Because it is easier and faster! There is no need to set the size of the window or change the graph type. In most cases, the Data & Statistics application has all of the features that you need. Plus, it has some nice statistical analysis tools, and the scale is automatically labeled and formatted.
Give these ideas some consideration. Also, with a bit of practice using both applications, you will surely gain a better understanding of which application best suits your needs.