From the beginning, the Standard League has become the basic game mode of Path of Exile. Other characters you encounter on the journey may have super powers. There is a mature economy where almost everything can be purchased at a price. You may not be able to afford the price temporarily, but you can Buy POE Currency at POECurrency to gain more strength.
Every few months or so, a new challenge alliance is launched on the path of exile. These temporary alliances bring all players back to a level playing field with first-level roles and economic reset. From there, it is a game where you can use POE Currency to build powerful skills, then complete the main story and traverse the final content of the game until the next reset. After the league, all characters are relegated to the standard league for future use.
Challenge League is also how Grinding Gear Games introduces new game mechanics into the "Path of Exile". From unique encounters to new craftsmanship, these can be anything. At the end of the league, new technicians are usually transferred to the core game, although they can perform major overhauls before joining new technicians.
Both Standard League and Challenge League have hardcore options. In this pseudo permadeath alliance, your character can only live one life. Nothing will be lost after death; your role will only be banished to the Standard League and will never be played again. You can purchase POE Currency, which will save you a lot of time.
Both Standard League and Challenge League have Solo Self-Establishment (SSF) options. Although PoE usually requires very little group interaction to play, SSF can completely cut off the interaction between your character and other characters. Only you are against everything that Wraeclast can bring to you.