What is data?

Data (data) refers to symbols that record objective events and can be identified. They are physical symbols or combinations of these physical symbols that record the nature, status and mutual relationships of objective things. Data is the result of facts or observations, a logical induction of objective things, and unprocessed raw material used to represent objective things.

Data (data) is the result of facts or observations, a logical induction of objective things, and the unprocessed original material used to represent objective things. . Data can be continuous values, such as sounds and images, which are called analog data; they can also be discrete, such as symbols and text, which are called digital data.

Data refers to symbols that record objective events and can be identified. They are physical symbols or combinations of these physical symbols that record the nature, status and mutual relationships of objective things. It is a recognizable, abstract symbol.

It not only refers to numbers in a narrow sense, but also to a combination of words, letters, digital symbols, graphics, images, videos, audios, etc. with certain meanings. It is also the attribute, quantity, location and other characteristics of objective things. Abstract representation of interrelationships. For example, "0, 1, 2...", "cloudy, rainy, falling, temperature", "students' file records, cargo transportation status", etc. are all data. Data becomes information after processing.

In computer science, data refers to the general term for all medium of symbols that can be input into a computer and processed by a computer program. It is a number, letter, symbol and analog that has a certain meaning and is used to input into an electronic computer for processing. A general term for quantity, etc. Computers store and process a wide range of objects, and the data representing these objects are becoming increasingly complex.

In computer systems, data is represented in the form of binary information units 0 and 1.

Classification

1. Classified by nature

①Positioning, such as various coordinate data;

②Qualitative , such as data representing the attributes of things (residential areas, rivers, roads, etc.);

③Quantitative, data reflecting the quantitative characteristics of things, such as geometric quantities such as length, area, volume, or physical quantities such as weight and speed;

④ Timing data that reflects the time characteristics of things, such as year, month, day, hour, minute, second, etc.

2. Divided into

according to the form of expression ① Numerical data, such as various statistics or measurement data. Digital data are discrete values ​​within a certain interval [3];

②Analog data, composed of continuous functions, refers to physical quantities that continuously change in a certain interval, and can be divided into graphic data (such as points , line, surface), symbol data, text data and image data, etc., such as the volume of sound and changes in temperature.

3. According to the recording method, it is divided into

maps, tables, images, tapes, and paper tapes. According to the digital method, it is divided into vector data, grid data, etc. In a geographic information system, the selection, type, quantity, collection method, level of detail, credibility, etc. of data depend on the system application goals, functions, structure, and data processing, management, and analysis requirements.

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