There are many ways to say God in Hebrew. The most common among Jews is Hashem (ה׳) or Elohim (אלוקים)The word for god (lower case g) is elil (אליל) and the plural is elilim (אלילים)
The Jews (formerly called Hebrews) worship one ethical God who according to tradition and Hebrew scripture, created the universe. Modern Jews understand God in many different ways.
I am going to assume that your question is what is the difference between these two, in which case the answer is relatively simple. A Greek god has its reign over one specific aspect of creation (ie:...