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
Mal 2:10
El Yeshuati - The God of My Salvation
Isa 12:2
Immanuel - God Is with Us
Isa 7:14
El Hannora - The Awesome God
Neh 9:32