The Manchester Arena Inquiry was established to investigate the deaths of the victims of the bomb attack in 2017.
22 people died and hundreds were left injured and traumatised after suicide-bomber Salman Abedi detonated a device following an Ariana Grande concert at 10.31pm on 22 May.
The victims were aged between eight and 51.
Abedi was known to the security services and the inquiry will also look at his background and radicalisation, as well as the preventability of the attack.
The bomber's brother, Hashem Abedi was jailed for life in August 2020 with a minimum 55 years before parole, for his part in the deadly bomb plot, which he has now admitted.
It began on 7 September 2020 and finished on 15 March 2022.
What will the Inquiry look at?
The Manchester Arena Inquiry is an independent public inquiry, established on 22 October 2019 by the Home Secretary.
It will investigate the circumstances leading up to and surrounding the terror attack, looking at how the 22 people died. It has the same scope as the inquests.
It will also "make any such recommendations as may seem appropriate".
The Inquiry will examine evidence about:
The arena complex and security arrangements
The planning and preparation for the attack
The emergency response
The detonation and its effect
The experience of each of the 22 people who lost their lives
The background and radicalisation of Salman Abedi
The preventability of the attack
Opening the inquiry in September 2020, chair Sir John Saunders said it was, "an exercise in establishing the truth."
He said: "If I conclude things went wrong then I shall say so, but we are not looking for scapegoats. We are searching for the truth."
Who is charing the inquiry?
Sir John Saunders is chair of the inquiry.
He was initially appointed as coroner of the inquests before Home Secretary Priti Patel appointed him as chair of Inquiry in October 2019.
The retired High Court judge is currently Vice Chair of the Parole Board.
Why was the Inquiry established?
The inquiry was established to allow a "full, fair and fearless" investigation into terror attack.
It followed a number of pre-inquest hearings into what was then the Manchester Arena Inquests.
Coroner Sir John Saunders requested that the Home Secretary converted the inquests into a public inquiry to allow some evidence to be disclosed in private sessions - which could not be done at an inquest.
During a pre-inquest hearing he said disclosing some evidence in public would "assist terrorists" in carrying out similar acts, adding that an "adequate investigation" could not be conducted within the frameworks of the inquests.
How will the conclusions of the inquiry be given?
The conclusions of the inquiry will be given via a report split into three volumes.
The first volume, addressing the security at the arena was released at 2pm on 17 June.
The second, addressing the response of the emergency services, will be released at 2.30pm on 3 November 2022.
The third, addressing the radicalisation of Salman Abedi, will be released at a later date.
Why are the reports staggered?
Sir John Saunders said the importance of the issues concerned meant he would not wait until the inquiry had finished to begin giving his findings.
He also stated that he was publishing the first volume to allow time to consider recommendations which can feed into the Government consultation on the 'Protect Duty'.
The public consultation will look to develop plans to make it a legal requirement for public places to improve security measures, as well as encompassing Martyn's Law.
Martyn’s Law - named after one of the attack's victims Martyn Hett and created by his mother Figen Murray - would make it a legal requirement for venue operators to consider the risk of a terrorist attack and take steps to protect the public.
Sir John told the inquiry he would set out recommendations for the Protect Duty in relation to arenas only.
He said: "I have made recommendations in the report... as to the Protect duty, but in order to avoid people having unduly optimistic views about what I’m going to deal with, I am only dealing with recommendations as to the Protect duty as it applies to similar areas to the arena, so places where public performances are being carried on and where they are large arenas."
He added: "I will deal, and I hope I’ve dealt in some detail, with the sort of recommendations of the Protect duty which I think are appropriate for places like the arena, but I have not gone on to consider everywhere."