The Major Arcana
A study of the Major Arcana as a system.
A standard tarot deck has 78 cards. The Major Arcana are the first 22 cards. They are powerful images that represent archetypes existing in the collective unconscious. The Major Arcana are numbered 0-21, usually in Roman numerals 0-XXI.
Some people see them as a staircase with 22 steps, each being a lesson you must learn to advance. This is seemingly why they are referred to as Keys - each one unlocks a door on The Fool's Journey.
It is widely understood that Key 0: The Fool exists outside of the other 21 Major Arcana cards, and is both the beginning and the culmination of the trump cards. Because of this, some decks place Key 0 as the first card of the deck, and some place it right after Key 21: The World.
The Major Arcana work as a system. You can lay them out in sequential order and see a pattern emerge. Generally, the order is seen as three rows of 7 cards, plus The Fool.
Keys 1-7 can be seen as the base human conditions on earth. Many people will spend their whole life in this first row energetically.
Keys 8-14 is where higher energies start to come in. When shadow work has been done and people start to see glimpses of what life could be if they harnessed their own psyche and the world around them.
Finally, Keys 15-21 represent the archetypes within divinity and how they are reflected back in us. As above, so below.
Here's some pictures of the Major Arcana lined up from some of my decks.
Golden Universal Tarot (Rider-Waite) by Lo Scarabeo ↓

Dark Wood Tarot (Bulgarian Edition) by Sasha Graham and Abigail Larson ↓

Prisma Visions Tarot ↓

Tarot of the 78 Doors by Pietro Alligo ↓

I really love the different decks I have, and I like using them together. Because the illustrations are so different, different symbols come out to me depending on the deck I use.
On My Study Table
What I used in this study session.
Decks used:
Golden Universal Tarot (Rider-Waite) by Lo Scarabeo
Dark Wood Tarot (Bulgarian Edition) by Sasha Graham and Abigail Larson
Prisma Visions Tarot
Tarot of the 78 Doors by Pietro Alligo
Books referenced:
The Windows of Tarot (1973) by F.D. Graves
How to Read Tarot (2017) by Fall River Press
Holistic Tarot (2015) by Benebell Wren
Tarot: Card for Divination, Wisdom and Self Discovery (2022) by Nikkie Jay
Courses:
Tarot Masterclass by Taroverse