RetailEdge has the ability to store credit card information if you want to. Storing credit card information with the customer and/or transaction can be useful for returns etc. It is up to you.
If you want to prevent RetailEdge from storing credit card information you can do this by:
Choosing Purge|Credit Card Data from the Tools menu.
Then Edit your location from Tools|Settings|Locations. On the Misc tab there is an option to Allow or Not Allow storing of limited credit card data.
Whether you store credit card information in RetailEdge will effect what form (SAQ) you need to fill out for PCI compliance.
Both partners we work directly with (PPI and MPS) have companies that they work with that will help you with PCI Compliance and will do all the paperwork for you and the quarterly port scans to document compliance.
They will ask you which form you need to fill out. If you are storing credit card data, then you would need to fill out the more detailed form.