Difference between że and iż ?

Please, does someone can help me to identify the difference between this both words?

They are pretty much the same. 'iż' seems to be more old-fashion or formal version of 'że' and it isn't used much these days (unless in literary works). When speaking, a Polish person isn't going to use 'iż' at all; they will always use 'że' instead.

Thx :3

"Iż" actually is being used a lot in modern polish. Since we shouldn't repeat words in one sentence we use both of them to make text look neat.

Example:

Mama powiedziała, iż Tato juz wie, że obiadu nie będzie.

There is no difference! "Iż" is more snobish:) if you want to look wiser say "iż";)