A cheesecake is a large family of sweet, cheese-based desserts, and is not a pie.
Cheesecakes are generally made with soft, fresh cheeses such as mascarpone. Other ingredients such as sugar, eggs, and cream are often mixed in as well. Flavourings such as rum or chocolate may be added, and a fruit topping, like strawberries, are frequently added. Typically, the filling or topping covers a base, which may be made of either pastry, or pulverised cookies/crackers/digestive biscuits.