The List Configuration application is used to create and maintain Lists.
When you run a report for a List you are, in effect, running a report for a list of Accounts. This makes the reporting process easier, since you can run one report for a number of Accounts instead of running a separate report for each Account.
If you are going to run a Custom Report using a List, you should use the List Configuration application to setup a List with Accounts
that are configured similarly. This will ensure that inputs and data will be displayed in a similar fashion on the report.
List Configuration Application Overview