1, Hallelujah is a word from Christianity, which is often used to praise God or express gratitude and praise to God. Amen is a word in Judaism and Christianity, which is used to express approval, affirmation and recognition of prayer or declaration.
2. Hallelujah is mainly used for religious worship and hymns. It is widely used in Christian churches and places of worship to express worship and praise to God. Amen is more often used in prayer, declaration or speech, as a conclusion to express affirmation and approval of what is said. In church, Amen is used to respond to the priest's prayer or sermon.