Cheesecake is predominantly listed as a dessert in its Wikipedia infobox. That classification reflects the sweet, cheese-based versions most people mean when they use the word cheesecake.
The standard dessert contains a soft fresh cheese, such as cream cheese, cottage cheese, mascarpone, quark, or ricotta, along with eggs and sugar. It may sit on a pastry, sponge-cake, cookie, or graham-cracker base. Fruit, chocolate, spices, and whipped cream are common additions.
The classification is not absolute because savory cheesecakes also exist. Smoked-salmon cheesecake, for example, is generally served as an appetizer or buffet item rather than as a sweet course. That exception explains why the infobox qualifies dessert as predominant instead of presenting it as the only possible course. Regional styles range from New York cheesecake to Japanese soufflé-style cheesecake, but they are still normally treated as desserts.