Annuity Rest Defenition

Some of us may not know about the rest pengertain annuity or annuities definitions rest. Some literature does mention that in a world of credit known as the annuity system rest. However, due to diverse backgrounds of the users home loan, home loan users may not know the rest of the term annuity.
Are these terms related to payment systems or just a term in the world of credit. Does the term is necessary when relating to the payment system so it’s good to know the intent of the user home loan term.
According to a property book I have ever read, rest annuity system means the calculation of effective interest charging with an annual period. If the debtor pays more to the loan principal, then by itself will get a reduction of the burden and the exact time of the settlement would end more quickly than the grace period. Only, of course be better if we use a system of Islamic mortgages. But at least from here we can know the rest will be the definition of an annuity or annuities understanding rest.