They provide a code that you need to redeem at a home depot sponsored site. It leads you to a printable coupon so you print and take it to the store. The bar code scans easily..else they can always type in the GC number.
Note that Swagbucks Home Depot eGift Card is issued with $xx USD [US dollar] rather than CAD [Canadian Dollar] so a slight sensitivity towards how both dollars are doing in the market.
There is no expiry on the coupon I received.