Hardware and Software

Hardware is computer machinery and equipment, including memory, cabling, power supply, peripheral devices, and circuit boards. Computer operation requires both hardware and software. Hardware design specifies a computer's capability; software instructs the computer on what to do. The advent of microprocessors in the late 1970s led to much smaller hardware assemblies and accelerated the proliferation of computers. Today's personal computers are as powerful as the early mainframes, while mainframes are now smaller and have vastly more computing power than the early models.
Software is a term for instructions that tell a computer what to do. Software is the entire set of programs, procedures, and routines associated with the operation of a computer system, including the operating system. The term differentiates these features from hardware, the physical components of a computer system. Two main types of software are system software, which controls a computer's internal functioning, and application software, which directs the computer to execute commands that solve practical problems. A third category is network software, which coordinates communication between computers linked in a network. Software is written by programmers in any number of programming languages. This information, the source code, must then be translated by means of a compiler into machine language, which the computer can understand and act on.
CPU (in full central processing unit ) is the principal component of a digital computer, composed of a control unit, an instruction-decoding unit, and an arithmetic-logic unit. The CPU is linked to main memory, peripheral equipment (including input/output devices), and storage units. The control unit integrates computer operations. It selects instructions from the main memory in proper sequence and sends them to the instruction-decoding unit, which interprets them so as to activate functions of the system at appropriate moments. Input data are transferred via the main memory to the arithmetic-logic unit for processing (i.e., addition, subtraction, multiplication, division, and certain logic operations). Larger computers may have two or more CPUs, in which case they are simply called “processors” because each is no longer a “central” unit.
Database is the collection of data or information organized for rapid search and retrieval, especially by a computer. Databases are structured to facilitate storage, retrieval, modification, and deletion of data in conjunction with various data-processing operations. A database consists of a file or set of files that can be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage. Users retrieve database information primarily through queries. Using keywords and sorting commands, users can rapidly search, rearrange, group, and select the field in many records to retrieve or create reports on particular aggregates of data according to the rules of the database management system being used.