The Catechism, quoting Lumen Gentium, tells us that, "The Eucharist is "the source and summit of the Christian life" (CCCC 1324).
A Holy Hour is spending an hour devoted to prayer in the presence of the Holy Eucharist where Jesus Christ is truly present in His body, blood, soul, and divinity.
“The purpose of the Holy Hour is to encourage a deep personal encounter with Christ. The holy and glorious God is constantly inviting us to come to Him, to converse with Him, to ask for such things as we need and to experience what a blessing there is in fellowship with Him.” (Bishop Fulton Sheen)
"Why (And How) to Bring Your Kids to Adoration" by Catholic Link