There are commonly multiple values you may be looking at and they are all different.
Appraisal value is what an appraiser determines the value is for a lender with a specific contract price already in mind. It may are may not be the selling price. Appraisals are "opinions of value" and not facts of value. Two different appraisers will come to two different opinions. Appraisals can be disputed due to inaccuracies, errors or new information coming available. Sometimes disputing a lower than contract value pays off, other times the appraiser digs in.
Assessed value is what a local city or county uses for taxation purposes and is not useful for determining a list or offer price. No one from the city or county investigates the home like an appraiser and these values can be all over the map. I often hear people refer to this as an appraised value, but it's not.
List price is a strategy for sellers. Some are high, hoping for an offer. Some are low, hoping for a bidding war. Some are in the middle.
Selling price is what a willing and qualified buyer agrees to pay to a willing and able seller. This is generally the actual market value of a home, if the marketing has been done properly and professionally.
I hope this explains things a bit more. Hopefully you have a great agent who can explain more about any specific homes you're considering.