Because is formal and cause is informal. Why did you eat my cookies? Because I was hungry. Cause/ 'Cause/ 'Cos/ Cuz I was hungry. ^Alternate spellings, the last is text slang. You may see the middle two if you're reading a book that tries to spell out an American southern drawl. To be safe always use because, there is no real need to use cause (UNLESS you're using in the context of cause and effect...)

'Because' is normal, correct written English. 'Cause' is what 'because' sounds like when we drop the 'be' part in relaxed informal speech. 'Cause' - when used to replace 'because' - is not a real word. Nor is 'cos' or worse still, 'coz'. These are written imitations of the sounds of spoken language, similar to 'dunno' 'wanna' and other non-existent words. Don't use them.

Ras is absolutely right. I'd also recommend using because in written English, and 'cause in spoken English.

there is no difference really. 'Cause' is just short for because

They are completely different words with different meanings. http://www.wordreference.com/definition/because http://www.wordreference.com/definition/cause