About leakage current, standby current and current budgeting
In general, inputs are ideally regarded to be sensitive voltage only, with infinite input resistance. Of course, real devices have finite impedances, and the current that flows into or out of them is called "input leakage current".

Similarly, some outputs can be switched off or "tristated", and in this state, they're supposed to have infinite resistance as well. But again, real devices have finite resistances, and the current that flows into or out of them is called "output leakage current".

If you want to talk about power consumption of a particular device, you'll have to provide more detail about the device in question. In general, you'll need to look up how much current it draws in each of its different modes of operation (e.g., sleep, standby, reading, writing), and multiply these values by the percentage of time it's going to spend in each of those modes in your particular application, then add up those products to get a total.