It is the method used to recruit new heroes or hero fragments in the game.
Each recruitment banner contains different pools and heroes and requires the appropriate Fate stones to recruit.

Types of Recruitment Lists:
Advanced Recruitment:
This is a permanently available banner that contains rare and epic heroes, along with resources and accelerations. This type requires the use of Advanced Fate Stones.
Epic Recruitment:
Also permanently available, this banner includes legendary, epic, and rare heroes, as well as resources and accelerations. It requires the use of Epic Fate Stones.
Legendary Recruitment:
This banner contains all the heroes in the game, along with badges, tomes, and training guides. It requires the use of Legendary Fate Stones.
Important Notes:
In the Legendary Recruitment banner, you are guaranteed to receive a legendary hero every 10 recruitment attempts.

You can check the contents of each banner by clicking the "Rewards Preview " button and then clicking "View odds" to see the chances of obtaining each type of reward.