According to the writer of Chronicles, this verse tells us about ten big water bowls that were made for washing. Five bowls were on one side and five on the other side, and they were used to clean the things given to God, while a special big bowl was for the priests to wash themselves.
2 Chronicles 4:6: He made also ten lavers, and put five on the right hand, and five on the left, to wash in them: such things as they offered for the burnt offering they washed in them; but the sea [was] for the priests to wash in. [such...: Heb. the work of burnt offering]
1 Kings 7:38 describes ten lavers instead of the one sea mentioned in 2 Chronicles 4:6.
1 Kings 7:38: Then made he ten lavers of brass: one laver contained forty baths: [and] every laver was four cubits: [and] upon every one of the ten bases one laver.