Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother in Islam, we would like to thank you for showing keenness on knowing the teachings of Islam, and we appreciate the great confidence you have in us. May Allah enlighten our hearts with the light of Islam!
With regard to your first question, Sheikh Hamed Al-Ali, instructor of Islamic Heritage at the Faculty of Education, Kuwait and Imam of Dahiat As-Sabahiyya Mosque, answers:
Literally Al-Barzakh means interval or a barrier between two things. Allah Almighty says: “Between them is a Barzakh (Barrier) which they do not transgress.” (Ar-Rahman 55:20)
Technically, it stands for an intermediary stage between this life and another life in the Hereafter; it’s an interval between death and the Day of Resurrection. Allah says: “Before them is a Partition till the Day they are raised up.” (Al-Mu’minun 23:100)
This does not mean that there would be special places for every soul, but the souls of dead people are in different places according to the level of their faith: some of them will be on the highest paradise with the souls of Prophets and martyrs; some believers will be in a particular place in Paradise before the Day of Judgment; some will have their graves like gardens of Paradise and some will have it like pits of the Hell-Fire. All of these cases and states of people will be in the period of Al-Barzakh, each one according to the status of his faith.
As for your second question, Sheikh Faysal Mawlawi, the late deputy chairman of the European Council for Fatwa and Research, answers:
The dead person does not know anything of the life of living people because he or she lives in a completely different world. However, it is reported that the dead person feels the footsteps of those who walk over him or her. It is narrated that the Prophet (peace and blessings be upon him) looked at the people of the well, in which the bodies of the disbelievers killed in the Battle of Badr were thrown and said, “Have you found true what your Lord promised you?” `Umar asked, “You are addressing dead people.” The Prophet replied, “They hear better than you do, but they cannot reply.” (Al-Bukhari)
These narrations refer to the period that closely follows the death of a person, but after that, the deceased moves completely to a new different world where he or she will not be aware of anything of what happens at this life. This may be confirmed by the verse: “You cannot reach those who are in the graves.” (Fatir 35:22)
Allah Almighty knows best.