What is a staging table?

staging tables are just database tables containing your business data in some form or other. Staging is the process of preparing your business data, usually taken from some business application. For your average BI system you have to prepare the data before loading it. A staging table is essentially just a temporary table containing the business data, modified and/or cleaned. Depending on your actual case you may have several staging tables from different source systems that then are combined into the resulting fact table for the BI system.