Monterey jack cheese is a relatively mild white cheese. Here is definition I found on cooking.com:

Monterey jack cheese, made from whole, partly skimmed, or skimmed cow's milk, is a semisoft white melting cheese with a mild flavor and buttery texture. This California specialty was developed in the mid-19th century by Monterey farmer David Jacks as his own version of a cheese made by the friars in the Spanish missions.