Meaning
That which was originally used in the tabernacle was of brass (rather copper; Heb. nihsheth), made from the metal mirrors the women brought out of Egypt (Ex 38:8). It contained water wherewith the priests washed their hands and feet when they entered the tabernacle (40:32). It stood in the court between the altar and the door of the tabernacle (30:19, 21).
In the temple there were ten lavers used for the sacrifices, and the molten sea for the ablutions of the priests (2Chr 4:6). The position and uses of these are described 1Kings 1:7-39; 2Chr 4:6. The "molten sea" was made of copper, taken from Tibhath and Chun, cities of Hadarezer, king of Zobah (1Chr 18:8; 1Kings 1:7-26).
No lavers are mentioned in the second temple.