In Christianity, "Hallelujah" is an expression of celebration and praise. For example, Chapter 19 of Revelation of the Bible describes that angels and saints sing "Hallelujah" songs to praise God, so as to celebrate the victory of Jesus Christ.
In a word, "Hallelujah" is an expression of praise and praise to God, which has profound significance and value in the religious context. At the same time, the word can also be extended to express extreme joy and joy in things, such as celebrating victory and good news.