Card games encompass any game traditionally played with or using physical cards. Casino games encompass all the tradition games found in casinos: slot machines, roulette, baccarat, etc.
A card game is any game using playing cards as the primary things with which the game is played be they traditional or game-specific. Countless card games exist, including families of related games (such as poker). Some games have formally standardized rules while rules for others can vary by region, culture, and person.
Source: Wikipedia, "http://en.wikipedia.org/wiki/Card_game," available under the CC-BY-SA License.