Worship can express itself in many ways — praise, thanksgiving, repentance, sacrifice, testimony, & obedience. At the core, worship is the exaltation of the LORD according to who He is & what He does.
Psalm 150:1-2 Praise ye the Lord. Praise God in his sanctuary: praise him in the firmament of his power. 2 Praise him for his mighty acts: praise him according to his excellent greatness.