What is the difference between hardware and software?

First, software is a logical product, which is essentially different from hardware products.

Hardware is a tangible physical component or device. When developing hardware products, people's creative activities are manifested in transforming raw materials into tangible physical products.

Software products exist in the form of programs and documents, and their functions are embodied by running on computers. In the process of software product development, people's production activities are characterized by creatively abstracting the solution model of the problem, then writing the program according to the solution model, and finally getting the result of solving the problem through debugging and running the program. The whole production and development process is completed in an invisible way, and the visibility is extremely poor, which brings great difficulties to the management of software development and production process.

Second, the quality of software products is different from that of hardware products.

There are two different ways to reflect quality. Hardware products can be mass-produced after the design is finalized, and the quality of products can be guaranteed through the quality inspection system. But once the production process goes wrong. Hardware products may be scrapped due to quality problems. However, software products cannot be produced by traditional manufacturing industries. As far as the current software development technology is concerned, software production is still "customized" and can only be designed or realized for specific problems. But software loves you. Once the product is realized, its production process is just copying, and the quality of the copied software is the same. Even if the designed software has quality problems, the product will not be scrapped. Through modification and testing, "scrapped" software can be "repaired" and put into normal operation. It can be seen that the quality assurance mechanism of software is more flexible than that of hardware.

Third, the cost structure of software products is different from that of hardware products.

In the cost composition of hardware products, tangible materials account for a considerable proportion. As far as the life cycle of hardware products is concerned, design and production account for the vast majority of the cost, and after-sales service only accounts for a small part.

Software production mainly depends on mental work. In the cost composition of software products, human resources account for a considerable proportion. The production cost of software products is mainly in development and research. After the successful development, the product production is simple, and mass production can be realized through replication.

4. The failure curve of software products is different from that of hardware products.

Hardware products have aging and depreciation problems. When a hardware component is worn, it can be replaced with a new one. Hardware will eventually be eliminated because of the wear and tear of main components.

As far as software is concerned, there is no problem of depreciation and wear, and it can be used permanently if necessary. But the troubleshooting of software faults is much more complicated than that of hardware faults. Software failures are mainly caused by errors in software design or coding, and must be redesigned and coded to solve the problem.

In the initial stage of software development, there is a high failure rate, which is mainly caused by unrealistic demand analysis or design errors. When the errors in the development process are corrected, the failure rate will drop to a certain level and remain relatively stable until the software is abandoned. When the software is greatly changed, the failure rate will also rise sharply.

Most of the software is customized.

Once the design of hardware products is finalized, its production technology, processing technology and process management are determined, which is convenient for the standardization and serialization of mass production of hardware products. Because hardware products have a standard framework and interface, users can integrate, assemble and replace products from any manufacturer.

Although software product reuse is the goal pursued by the software industry, several leading software companies have also established some technical standards for software component reuse in some local areas. For example, CORBA of OMG, COM of Microsoft, J2EE of sun and so on. However, software substitutes cannot be widely used at present. Most software is still customized for specific tasks or users.