Years ago Disney sold three types of GC:
Food & Beverage - Which I've never seen before.
Merchandise - Disney Store
General - Disney
I had a DP which included a link to the above but it became invalid, perhaps it happened when Disney closed all the Disney Stores and/or revamped their website, idk.
Upon my Google search I found an old 2012 response:
Plan to use your Disney "Store" gift card ahead of time at your local Disney Store to pick-up plenty of Mickey merchandise for your Disney vacation! WDW link
Last I read, Disney Store GC could not be combined with DGC. They could not be used to purchase tickets or resort stays, just merchandise.