Literally "all power" is power with no limits. Unlimited power.
Almighty, or ruler of all. Used of God only.
2 Cor 6:18 And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
Diggin Deeper
In Revelation, the Lord our God, the Almighty. The word is introduced in the Septuagint as a translation of Lord (or God) of hosts.
Rev. 19:6 And I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunderings, saying, Alleluia: for the Lord God omnipotent reigneth.
Jer. 5:14 Wherefore thus saith the LORD God of hosts ....
Amos 4:13 For, lo, he that formeth the mountains, and createth the wind, and declareth unto man what is his thought, that maketh the morning darkness, and treadeth upon the high places of the earth, The LORD, The God of hosts, is his name.
