I will explain what atlas is in general (what each thing is), primarch types, and common TERMS. If you wish to know to how navigate atlas, head over to Navigating Atlas !
Atlas is another part of War Dragons which a few higher league teams have. Not all teams have and it's a long road to obtain it.
You know if you have atlas because above the WAR icon, there will be an icon with a scroll with a sword through it (as shown).
Atlas can be used to get more resources such as timers, egg tokens, and dragon XP. Atlas also comes with additional goodies such as riders and primarchs.
In order to enter atlas, you will need atlas access. If you have the atlas icon, then you have access. If you don't, that means your current guild doesn't have access.
When you create your own team, you will start in Bronze league. You will have to be in PLATINUM II for at least two weeks before you can gain access.
Glory is obtained by attacking other players in atlas. This glory acts like dragon xp, except it used towards level up your primarch.
Primarchs are like chess pieces. They are your "Queen" that allows you to move through atlas to attack people for glory. There are five types of primarchs: Fighter, Trapper, Destroyer, Seiger.
Castles are owned by atlas teams who are NOT Pirates. Castles help you get more crafting shards, gold, etc.
In atlas you will start to get crafting shards. These shards can be used to craft armor in the forge for your riders. You need to match the element to the dragon element for riders. For example wind gear on Krelos the Wind Sorcerer.
In addition to getting primarchs, you will begin to get atlas riders. You can hire them using either blue or red stones from the atlas seasonal branch.
When an enemy dragon goes to attack a castle, the Taunter will become the main focus for the enemy to defeat.
Trappers can block the Taunters abilities and move a prim that you trapped towards you so it can only attack you while the trap is active.
Fighters/ Destroyers are the main type of primarch. They have no special abilities.
A seiger has a powerful attack power, but a very low defense power.
In this right hand drop out menu, you will be able to see LEADERBOARD, CASTLES, ATTACK LOGS(manage), SETTINGS, MISSIONS, and ALLIANCES.
Just like Dragon Quests, you can send your atlas riders on mission for atlas prizes and general prizes.
CASTLES will show you the list of castles your team owns, if any.