Which of the following best describes an easement?

An easement is best described as a right to cross or use someone else's land. This legal right allows the easement holder to utilize a portion of another person's property for a specific purpose, such as access to a road, utility lines, or drainage. Unlike ownership, which confers a bundle of rights including the ability to sell or modify the land, an easement grants permission for a specific use while the underlying ownership remains with another party. This distinction is crucial in real estate, as easements can significantly impact property access and usage without transferring ownership.

The other options pertain to concepts that do not accurately define an easement. A physical structure, for instance, refers to tangible items built on land, which is separate from the legal rights conveyed by an easement. Ownership of land denotes full control over the property, which contrasts with merely having an easement. Lastly, property tax is a financial obligation associated with ownership and does not correlate with the legal rights involving land use. Thus, the description of an easement as a right to cross or use someone else's land captures its essence in real estate law.