In Judaism, the Book of Exodus describes ten plagues striking Egypt before the Israelites left.
The plagues are water turned to blood, frogs, lice, wild animals, pestilence, boils, hail, locusts, darkness, and the death of the firstborn. They are presented as signs demonstrating God's power and pressuring Pharaoh to release the Israelites.
The number ten is especially prominent in the Passover Haggadah, which names each plague during the Seder. Some Jewish traditions symbolically reduce the amount of wine in a cup while reciting the list, because the celebration of freedom is tempered by remembrance of suffering.
The plagues are sometimes confused with the Ten Commandments because both are famous groups of ten in the Torah. They are separate episodes: the plagues occur in Egypt before the Exodus, while the commandments are given later at Mount Sinai.