This video describes well the difference between land value and property taxes: Why America’s Biggest Cities Are Littered With Vacant Lots.

Also, from the wiki page:

A land value tax (LVT) is a levy on the value of land without regard to buildings, personal property and other improvements upon it.[1] It is also known as a location value tax, a point valuation tax, a site valuation tax, split rate tax, or a site-value rating.

Some economists favor LVT, arguing they do not cause economic inefficiency, and help reduce economic inequality.[2] A land value tax is a progressive tax, in that the tax burden falls on land owners, because land ownership is correlated with wealth and income.[3][4] The land value tax has been referred to as “the perfect tax” and the economic efficiency of a land value tax has been accepted since the eighteenth century.[1][5][6]

In short, LVT taxes just the land value, where property taxes tax the total property value, including both land and improvement value. The idea of why LVT is better is because it makes it less profitable to simply hoard valuable urban land and resell later when it has appreciated. Instead, it heavily incentivizes people to develop new housing or businesses on valuable urban land, which helps combat the housing crisis.

It’s also progressive, hard to evade (you can’t hide land), economically efficient, incentivizes good things (development), and disincentivizes bad things (land hoarding and speculation). Even a milquetoast LVT has been shown to make housing more affordable.