Our ancestors lived places. They owned houses, they rented them, they owned land, they rented it to farm on or to build on. They owned their properties outright, or they paid mortgages on them. They paid taxes on them. They had property left to them through inheritance, which they either kept or sold. They gifted property to other people, usually (but, not always) family members. They moved and started the whole process of renting or owning property again. All of these things generated records, and these records can be incredibly useful in your genealogy journey.
Land records can tell you a lot of different things about a person or a family. It may even assist you in tracing generations of the same family line. You can trace the places a person lived, and use those locations to check for evidence of other family members following them there (or already being there when your ancestors arrived). You can learn about their relationships with friends, neighbors, and their community. You can learn about family relationships through land and property inheritance. You might even be able to find birth, death, and marriage dates that are otherwise lost, just by using land records. You might also be able to learn about new children in a family you previously did not know existed, or discern the maiden name of a female ancestor you were never able to find anywhere else. Land records are incredibly useful.
US federal census records from the mid-1800s onward will tell you if your ancestor owned or rented their property, and whether they had a farm or lived in a house (or a different type of dwelling place) in the city. These are good starting points for looking for land records. They will give you a definite location for your ancestor at a certain date in history. Once you find the appropriate land records for that place, those records may give you clues to other places to look for additional records on the same family or person, going either forward or backward in time.
While they are often overlooked by beginning genealogists who do not realize their value, land records are actually some of the most valuable and revealing genealogical records that exist. You just have to know where to look for them, and then for what to look for on them. Once you start delving into land records, you will undoubtedly wonder how you ever got along without them in your genealogy research. You will almost certainly come across some new information that excites you, at least occasionally. Land records are often full of wonderful genealogical surprises.
The wonderful thing about land records, in addition to the detailed genealogical information they might provide, is that they are usually readily available. Land records were kept by governments at the national, state, and local levels. Most of them have been well-protected and preserved, which means they are available for you to use.