What does Exodus 38:21 mean?

Here’s the record of everything used for the tabernacle, the tent where God met with his people. The Levites, under Ithamar (Aaron’s son), kept track of it all, just as Moses had instructed. Exodus 38:21 - Modern Text Bible

(This verse introduces the inventory, showing that everything was carefully accounted for by the Levites, following Moses’ leadership.)