The page layers are used to create various sections and page breaks in reports. I suppose when you create a dimension member in this area, one block of the current section of the hierarchy is created in your report
Context filter area use to filter various reports for separate contexts of information. When you create a member in the hierarchy in the context filter, one block with context selection is created in your custom report.
For example, This report can be used to analyze the gross profit metric by region. You can also add the order method web to context filter. Context filter configuration can be default applicable to a single object. If Suppose if you need to apply for two or more objects. You must select each of the objects and add dimension member
The Toolbox tab shows objects that allow users to display all data, They are charts, crosstabs, lists, etc. Customers can also create text items, blocks, hyperlinks, images, and labels.
This page navigation is enabled whenever if the reports are more than one page. This page navigation allows us to scroll up and down and go to the end of the report
This work area contains all the objects are dropped on the report. Users can use all the lists, layout components, charts components, etc. If the page view menu is enabled this work area shows the live data and so customers can interact with it in more conveniently. For instance, page design is enabled it will not show the live data.
Conclusion: With these key features you can be able to get a brief introduction of key areas and their information. You can learn and implement in Cognos online training