The corresponding certificate token you obtain after you supply a number of cetain encrypted currency to the market.
Users supply encrypted currencies to the market to provide liquidity, and obtain the corresponding rTokens. They receive interest yields by providing liquidity.
Users have to pledge rToken to the market before any borrow.
Users take back the rToken that pledged to the market.
Users return the rToken in exchange for corresponding encrypted currency that were supplied before, including interest yields as the reward for providing liquidity.
Users borrow encrypted currencies from the market at a certain interest rate.
Users repay the borrowed encrypted currency and the interest accrued during the borrow period.
Due to the fluctuation of the market price, the value of a user's loan may exceed that of his pledged assets. When that happens, the other users can use a lower price to obtain the user's pledged assets so that the user's debt that are not covered by pleged assets are repayed.