Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

What is the Differnce between Sorcery and Sorceries i have a hard time to find it out If a Sorcerness need a Source to do Sorcery ?

I will take a stab at an answer.
Sorcery is singular, and basically means magic or a type of magic.
Sorceries is plural, and would basically mean multiple types of magic.

Examples

1) Sorcery is a type or magic in DnD

2)a)Arcane and Invocations are a couple types of sorceries available to a mage.
Or
2)b)There are various sorceries a sorcerer can be born from depending on thier background.

Sorcery and magic can be interchangable outside of DnD. In various games sorcery and even sorceries have a specific defined meaning depening on the games rules. But, generally speaking, sorcery/sorceries are just other ways of saying magic.

Sorcerors use sorcery to cast various types of sorceries.

A good sauce always helps with the sorcery!