El Shaddai means power, strength, sufficient, and all-mighty. God gives this name of Himself to Abram so that Abram can better understand the characteristics of God.
Amy Grant wrote a timeless song in 1982 that still captures this beautifully. It launched her career almost as much as Abram. ;-) Watch 7 minutes and then listen to Amy's song.
https://www.youtube.com/channel/UCNijvDWAn2Wv2KFun2AnvCA