Mileage matters because it gives you a good indication of how much wear and tear a vehicle has been put through.
Typically, when comparing two otherwise similar vehicles, the one with the lower mileage will be the more appealing because the mechanical components will have suffered less wear. At the same time, the bodywork will have seen a reduced risk of dings and dents.
There’s no hard and fast rule, though, with plenty of other things to consider, so we’ll address these points too.