Marble cheese is a combination of orange and white cheese curd. A common incorrect assumption is that it is a combination of mozzarella

Mozzarella

Mozzarella is an Italian Traditional Speciality Guaranteed food product. The term is used for several kinds of Italian cheeses that are made using spinning and then cutting :...

  and cheddar

Cheddar

Cheddar is a large village and civil parish in the Sedgemoor district of the English county of Somerset. It is situated on the southern edge of the Mendip Hills, north-west of Wells. The civil parish includes the hamlets of Nyland and Bradley Cross...

 cheeses, when it is in fact entirely cheddar cheese.

As with most commercial cheddar cheeses, it is essentially processed cheese in order to satisfy demands of mass production. As well with most cheeses, It comes in rennet

Rennet

Rennet is a complex of enzymes produced in any mammalian stomach to digest the mother's milk, and is often used in the production of cheese. Rennet contains many enzymes, including a proteolytic enzyme that coagulates the milk, causing it to separate into solids and liquid...

-free and light versions.