What is Self-refresh?

A low-power DRAM state in which the DRAM refreshes itself to retain contents without commands from the memory controller, used during system sleep.

Self-refresh in the explanations

In self-refresh mode the DRAM refreshes itself using an internal timer, so the external clock and controller can be stopped, preserving data at low power while a phone or PC sleeps.
Which correctly describes the self-refresh mode of DRAM?
In self-refresh, the DRAM keeps refreshing itself with an internal oscillator, so contents survive even with the memory controller and interface circuits shut down.
Among DRAM power-saving states, which describes self-refres…