If we go back to the equations manager, we will notice a tab at the bottom titled Equations, as highlighted in the following screenshot:

This shows all of the equation applications we have in the model. It also gives us quick access to all of them in case we need to apply any change without needing to look up the actual part in the design tree. The first column shows the names of the dimensions. D1@Sketch1 refers to dimension 1 from Sketch1, which is listed in the design tree. 

You may think that it is not convenient for us to recognize these codes (for example, D1@Sketch1), especially when we build models that contain many different measurements and sketches. To make this process easier, we can change these names as we are inputting the dimensions. The following screenshot shows the dialog box we get when we enter a specific dimension, highlighting where we can change the name of that specific dimension. The following highlighted box will enable us to change D1. To change @Sketch1, we can rename the sketch entry found in the design tree:

Now, let's elaborate a bit more about design intent when using equations.