In real estate, a lot is a tract or parcel of land owned or meant to be owned by some owner(s). A lot is essentially considered a parcel of real property in some countries or immovable property (meaning practically the same thing) in other countries.

Possible owner(s) of a lot can be one or more person(s) or another legal entity, such as a company/corporation, organization, government, or trust. A common form of ownership of a lot is called fee simple in some countries.

Sometimes, some may refer to a lot as a rather small area of land that is empty except for pavement or similar improvement. An example would be a parking lot. This article covers lots as parcels of land meant to be owned as units by an owner(s).

A lot has defined boundaries (or borders) which are documented somewhere, but the boundaries need not be shown on the land itself. Most lots are small enough to be mapped as if they are flat, in spite of the curvature of the earth. A characteristic of the size of a lot is its area. The area is typically determined as if the land is flat and level, although the terrain of the lot may not be flat, i. e, the lot may be hilly. The contour surface area of the land is changeable and may be too complicated for determining a lot's area.

Something which is meant to improve the value or usefulness of a lot can be called an appurtenance to the lot. Structures such as buildings, driveways, sidewalks, patios or other pavement, wells, septic systems, signs, and similar improvements which are considered permanently attached to the land in the lot are considered as real property, usually part of the lot but often parts of a building, such as condominiums, are owned separately. Such structures owned by the lot owner(s), as well as easements which help the lot owners or users, can be considered appurtenances to the lot. A lot without such structures can be called a vacant lot, or an unimproved or undeveloped lot.

Lots can come in various sizes and shapes. Often a lot is sized for a single house or other building. Many lots are rectangular in shape, although other shapes are possible as long as the boundaries are well-defined. Methods of determining or documenting the boundaries of lots include metes and bounds, quadrant method, and use of a plat diagram. Use of the metes and bounds method may be compared to drawing a polygon. Metes are points which are like the vertices (corners) of a polygon. Bounds are line segments between two adjacent metes. Bounds are usually straight lines, but can be curved as long as they are clearly defined.

Many times, developers divide a large tract of land into lots to make a subdivision out of it. Certain areas of the land are dedicated (given to local government for permanent upkeep) as streets and sometimes alleys for transportation and access to lots. Areas between the streets are divided up into lots to be sold to future owners. The layout of the lots is mapped on a plat diagram, which is recorded with the government, typically the county recorder's office. The blocks between streets and the individual lots in each block are given an identifier, usually a number or letter.

Land originally granted by the government was commonly done by documents called patents. Lots of land can be sold/bought by the owners or conveyed in other ways. Such conveyances are made by documents called deeds which should be recorded by the government, typically the county recorder's office. Deeds specify the lot by including a description such as one determined by the "metes and bounds" or quadrant methods, or referring to a lot number and block number in a recorded plat diagram. Deeds often mention that appurtenances to the lot are included in order to convey any structures and other improvements also.

When the boundaries of a lot are not indicated on the lot, a survey of the lot can be made to determine where the boundaries are according to the lot descriptions or plat diagrams. Formal surveys are done by qualified surveyors, who can make a diagram or map of the lot showing boundaries, dimensions, locations of any structures such as buildings, etc. Such surveys are also used to determine if there are any encroachments to the lot. Surveyors can sometimes place posts at the metes of a lot.