What's the difference of gerd reflux and acid reflux and what can thay cause?

The same thing...: Gastroesophageal reflux disease (gerd; acid reflux is the same thing) is a condition in which the stomach contents (food or liquid) leak backwards from the stomach into the esophagus (the tube from the mouth to the stomach). This action can irritate the esophagus, causing heartburn and other symptoms. Long term, the chronic inflammation can put you at higher risk of developing esophageal cancer.

No short answer: They are essentially the same. They can cause chest pain (sometimes mistaken for a heart attack), esophagitis (inflammation and possible ulceration of the lower to upper esophagus, coughing, probably asthma. There is also a question whether it can cause barrett's esophagus which may be a precursor to esophageal cancer.