Law of Moses

The Priests were all sons of Aaron who was a son of Levi. The Levites were all the sons of Levi.

The chart shows all the sons of Levi:

Pictures from biblestudentdaily.com with permission

Pictures from biblestudentdaily.com with permission

Priests laying hands on the bull for a sin offering (Leviticus 4 v 15)

Pictures from biblestudentdaily.com

The Laver is called a Basin in many modern translations.

Priests washing at the laver.

Pictures from biblestudentdaily.org with permission

Inside the Holy and Most Holy place 

Layout of the camp

Images from Biblestudentdaily.com with permission.

The Altar in use

Pictures from biblestudentsdaily.com with permission.

Picture from biblestudentsdaily.com with permission.

The Lord clearly tells Moses what the purpose of the tabernacle is:

Exodus 25 v 8

8 Let them make me a sanctuary, that I may dwell amongst them.

The tabernacle was to be in the middle of the Israelite camp.