What does capacitance and resistance equals to? In some books it is written time, can you explain me it’s relation?

Dear student ....In RC (resistive & capacitive) circuits, time constant is the time in seconds required to charge a capacitor to 63.2% of the applied voltage. This period is referred to as one time constant.Time constant is known as tau(t), its relation is t= RC....With Regards ...Mahima ....(Askiitians Forum Expert )