A Qlik Sense application combines data in the form of a structured data model, visualizations, sheets, and stories. Dimensions, measures, and visualizations can be created as data items that can be reused between several visualizations (charts) and sheets (visualizations).

Let's take a look at each of these application components in brief. The components of an application are as follows: 

• Data model: A data model contains all the data that is loaded by the load script as well as several tables, each connected by unique fields. Every time we change the data load script, we reload the application to update the data model.
• Measures: Measures contain expressions that we can implement in visualizations. These expressions have one or several field aggregate functions, such as sum, avg, min, and max. Changes in the measure expressions affect all related visualizations. Measures are stored in the Master items library.
• Dimensions: Dimensions define how to group data in a visualization. We can create a dimension with one field, or we can create a hierarchical dimension with two or more fields. Changes in the dimension field affect all related visualizations. Dimensions are stored in the Master items library.
• Visualizations: Visualizations are charts and tables that are created in a sheet. Visualizations can use dimensions and measures stored as Master items. A visualization can also be created as a Master item to be reused across sheets.
• Sheets: Sheets contains visualizations for a single analysis. We can create several sheets, each one with a different analytical purpose.
• Bookmarks: Bookmarks allow us to save the current selection on a sheet. We can open an app and directly select a bookmark to go back to the saved selection and sheet. We can also use this as our initial selection when opening the app.
• Stories: We can create a presentation using snapshots of visualizations with specific selections combining several visualizations on each slide. We can also use the entire sheet as a slide. Stories can be exported to PDF or PPTX format for further modification.

When opening an application, we can see the overview interface. From there, we have direct access to the sheets, bookmarks, and stories that have already been created.

When working with Qlik Sense Desktop, or a non-published application in Qlik Sense Enterprise or Qlik Cloud, we are free to add new sheets to the application. These are called base sheets.

When working with a published application on Qlik Sense Enterprise, if we have the permission to create new sheets, we can also create a private sheet. This sheet can be published and explored by the other users. In the Qlik Cloud, we can only navigate the sheets on a published application.