field, in algebra

field, in algebra, set of elements (usually numbers) that may be combined under the operations of addition and multiplication so that it constitutes an additive group group, in mathematics, system consisting of a set of elements and a binary operation a+b defined for combining two elements such that the following requirements are satisfied: (1) The set is closed under the operation; i.e.
..... Click the link for more information. , the nonzero elements form a multiplicative group, and multiplication distributes over addition. The set of real numbers (see number number, entity describing the magnitude or position of a mathematical object or extensions of these concepts.

The Natural Numbers

Cardinal numbers describe the size of a collection of objects; two such collections have the same (cardinal) number of
..... Click the link for more information. ) and the set of complex numbers are both examples of fields.

field, in physics

field, in physics, region throughout which a force may be exerted; examples are the gravitational, electric, and magnetic fields that surround, respectively, masses, electric charges, and magnets. The field concept was developed by M. Faraday based on his investigation of the lines of force that appear to leave and return to a magnet at its poles (see flux, magnetic flux, magnetic, in physics, term used to describe the total amount of magnetic field in a given region. The term flux was chosen because the power of a magnet seems to "flow" out of the magnet at one pole and return at the other pole in a circulating pattern,
..... Click the link for more information. ). Fields are used to describe all cases where two bodies separated in space exert a force force, commonly, a "push" or "pull," more properly defined in physics as a quantity that changes the motion, size, or shape of a body. Force is a vector quantity, having both magnitude and direction.
..... Click the link for more information. on each other. The alternative to postulating a field is to assume that physical influences can be transmitted through empty space without any material or physical agency. Such action-at-a-distance, especially if it occurs instantaneously, violates both common sense and certain modern theories, notably relativity relativity, physical theory, introduced by Albert Einstein, that discards the concept of absolute motion and instead treats only relative motion between two systems or frames of reference.
..... Click the link for more information. , which posits that nothing can travel faster than light. In a field description, rather than body A directly exerting a force on body B, body A (the source) creates a field in every direction around it and body B (the detector) experiences the field that exists at its position. If a change occurs at the source, its effect propagates outward through the field at a constant speed and is felt at the detector only after a certain delay in time. The field is thus a kind of "middleman" for transmitting forces. Each type of force (electric, magnetic, nuclear, or gravitational) has its own appropriate field; a body experiences the force due to a given field only if the body itself it also a source of that kind of field. The reciprocity implied by Newton's third law of motion motion, the change of position of one body with respect to another. The rate of change is the speed of the body. If the direction of motion is also given, then the velocity of the body is determined; velocity is a vector quantity, having both magnitude and direction,
..... Click the link for more information. (equal action and reaction) is thus preserved. If two bodies exert a mutual force, they possess potential energy energy, in physics, the ability or capacity to do work or to produce change. Forms of energy include heat , light , sound , electricity , and chemical energy.
..... Click the link for more information. that depends on their relative positions; it is natural to regard this energy as residing in the field the bodies create.

field

In physics, a region in which each point is affected by a force. Objects fall to the ground because they are affected by the force of earth's gravitational field (see gravitation). A paper clip, placed in the magnetic field surrounding a magnet, is pulled toward the magnet, and two like magnetic poles repel each other when one is placed in the other's magnetic field. An electric field surrounds an electric charge; when another charged particle is placed in that region, it experiences an electric force that either attracts or repels it. The strength of a field, or the forces in a particular region, can be represented by field lines; the closer the lines, the stronger the forces in that part of the field. See also electromagnetic field.

A physical unit of data that is one or more bytes in size. A collection of fields make up a record. A field also defines a unit of data on a source document, screen or report. Examples of fields are NAME, ADDRESS, QUANTITY and AMOUNT DUE.

The field is the common denominator between the user and the computer. When you interactively query and update your database, you reference your data by field name.

There are several terms that refer to the same unit of storage as a field. A data element is the logical definition of the field, and a data item is the actual data stored in the field. For each data element, there are many fields in the database that hold the data items.

The Basic Unit of Storage
Technically, data elements describe the logical unit of data, fields are the actual storage units, and data items are the individual instances of the data elements as in this example. In everyday language, all three terms are used interchangeably. It's only when you read technical documentation on database management that you run across the proper use of these terms.

(data, database)

field - An area of a database record, or graphical user interface form, into which a particular item of data is entered.

Example usage: "The telephone number field is not really a numerical field", "Why do we need a four-digit field for the year?".

A database column is the set of all instances of a given field from all records in a table.