Qual è la differenza tra eftersom e därför att ?Sentiti libero di rispondere con un esempio.

They are both subordinating conjunctions and are used to explain the reason for what's happening in the main clause:

Jag gjorde det, därför att jag var tvungen.
Jag gjorde det, eftersom jag var tvungen.
I did it, because I had to.

The difference is that eftersom can be used in the beginning of the sentence as well, which därför att most often cannot:

Eftersom jag var tvungen, gjorde jag det.

Two bonus tips for you:

1. Därför att is often shortened to “för att”. För att has other meanings as well (expressing aim), so it's good to keep in mind that för att is sometimes just short for därför att. In speech this often becomes “fatt”.

2. Many learners of Swedish overuse eftersom and därför att. Keep in mind that there also is the co-ordinating conjunction “för”, which has the same meaning plus it's super short practical!

Jag gjorde det för jag var tvungen.

I hope this wasn't too confusing! Anyway, feel free to ask questions. :)