It depends.
Generally, DLR Discounts are generally available to all employees of The Walt Disney Company. However, our resort discounts tend to be seasonal, and only available during certain times of the year. However, the discounts on Merchandise and Food are available to anyone with a Perner and a Company ID Card.
Merchandise is 20% off if you've been with the company for less than 3 years, and 35% off after 3 years, at all DLR owned-operated Merchandise locations.
Food is 20% off for all Cast Members at all DLR owned-operated restaurants (with the exception of Outdoor Vending/Ventures stands), during standard operating hours.
WDW, on the other hand, tends to make many of their discounts available only to Florida-site Cast Members (Employees of The Walt Disney Company, or Operating Participants, who hold company IDs that are issued by Walt Disney World Access Control). The resort discount is available to all TWDC employees, as are the Merchandise and Food Discounts. However, things like the discounts at the Water Parks/Pleasure Island/DisneyQuest, and so on, are only available if you're a FL-site CM.
Merchandise is the same as the DLR, at all WDW owned-operated Merchandise locations.
Foods, is 20% off, at certain WDW owned-operated restaurants only (mainly Table Service and Resort QSR), and is only valid during certain times of the year, and certain times of the day.