Omniscience (or Omniscient Point-of-View in writing) is the capacity to know everything infinitely, or at least everything that can be known about a character including thoughts, feelings, life and the universe, etc. In monotheism, this ability is typically attributed to God. This concept is included in the Qur'an, where God is called "Al-'aleem" on multiple occasions. This is the infinite form of the verb "alama" which means to know. In Hinduism God is referred to as sarv-gyaata (omniscient), sarv-samarth (omnipotent) and sarv-vyapt (omnipresent); where sarv-gyaata means sarv (all) gyaata (knowing).
There is a distinction between:
inherent omniscience the ability to know anything that one chooses to know and can be known
total omniscience actually knowing everything that can be known.
Some modern theologians argue that God's omniscience is inherent rather than total, and that God chooses to limit his omniscience in order to preserve the freewill and dignity of