Land value tax is an idea by Henry George - the guy who coined the phrase "the rent is too damn high". His idea is among other things that a property tax discourages investment - one way to make money as an investor is to hold a plot of empty land in a desirable city centre location, watch it go up in value, and neither pay tax on any development on it nor bother with messy things such as tenants. Taxing the land value, according to George, removes that perverse incentive.
For a more detailed overview, I recommend Lars Doucet's review of George's Progress and Poverty, which won the Astral Codex Ten book review contest a year ago: https://www.astralcodexten.com/p/your-book-review-progress-a...
I really like the style, but you need to put an hour or so aside to read the whole thing. For me, it was definitely worth the time!