The potion effects you can obtain in Terraria are very important for conquering much of the world. Many boss fights and difficult encounters can be made easier with higher health regeneration, higher defense, quicker speed, immunity to fall damage, and many other effects. Understanding potions can help you deal with the fights you have a hard time with.
Potions can be complicated, but can also be made simple through organization and by using a glass bottle to check potion recipes with the guide. These recipes can save you a lot of time facing bosses and can save you materials by summoning bosses. Some of these potions can enable new strategies or completely trivialize encounters.