Like a marinade, a rub is a mixture of flavor agents created to infuse meats with extra taste. Unlike a marinade, a rub is not a liquid. A rub's ingredients (such as garlic, herbs, and spices) are chopped together to form a coarse paste, which is hand-rubbed onto a meat's surface, typically one to several hours before it is cooked.
A growing number of cooks prefer rubs to marinades because they impart more flavor and leach out fewer meat juices. And the meat's center is less likely to end up drab brown. However, a rub is less effective for tenderizing because it is less acidic and the tenderizing agents do not penetrate as deeply into the meat compared to marinades.
** Asian Cuisines