The oldest Semitic word for God, El's root meaning is power and strength.
You can compare it to the way we use the word "god" as a proper noun when referring to the one true God. The pagan tribes around and within Israel often used the word when they spoke of the mightiest god in their pantheon or the "Father God".
Some Notable Uses In The Bible:
El Echad - The One God
El Yeshuati - The God of My Salvation
Immanuel - God Is with Us
El Hannora - The Awesome God