Tax assessor
The local official who sets the assessed value of every property in town for tax purposes. The town appoints the assessor, but the duties are set by state law, and the assessor must hold a state Tax Assessor Certificate.
New Jersey example
Each New Jersey town has one assessor position. The assessor values your home as of October 1 and puts it on the town's assessment list. If your value looks wrong, call the assessor's office first. Once the list is filed with the county board of taxation, the assessor can no longer change it alone, so a formal appeal may be needed.
Official source
Handbook for New Jersey Assessors (NJ Division of Taxation, revised July 2024)
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.