That which in meditation one comes to naturally as the mind awareness ceases is called silence. In this inward process of discovering who we are, we find this silence. Another way is that there is not anything left in the mind’s awareness. This quietness exist beyond our normal noise. We usually go into a wandering state of the mind. This quietness or silence is beyond even the normal sleeping mind. As the great sage Patanjali (of the Yoga Sutras) states that sleep is an operation of the mind. This silence is yet beyond that quietness. That silence is a an experience of noticing it after sometimes having had such. It isn’t a deep experience of it. This experience is just a transition into the silence that exist even beyond this existence.
Eckart Tolle in the following video has a nice presentation. Please see below.