Dear Lissa,
Science you have written in English, I am obliged to response you in English.
Simply speaking, cheese ia a diary (milk) product. It is actually a curdled or coagulated caseine (milk protein) and the solution left (uncoagulated portion) is called whey. In order to coagulate caseine, a coagulating agent or a coagulant is used. Traditionally rennin / rennet extracted from calf abomasum (a part of a stamach) is used. Here an issue of halal/haram may arise. Other coagulants are enzymes (aspartic proteases) from microb (microbial rennet) or plants may also be used. In this case, the cheese is undoubtfully halal.