Beginning of Essay
A machine that performs tasks, such as mathematical calculations or electronic communication, under the control of a set of instructions called a program is a computer. Programs usually reside within and are retrieved and processed by 's electronics, and the prog ....

Middle of Essay
.... features from a digitally encoded laser disc. Computer programs, or applications, exist to aid every level of education, from programs that teach simple addition or sentence construction to advanced calculus. Educators use computers to track grades and prepare notes; with computer-controlled projection units, they can add graphics, sound, and animation to their lectures. Computers are used extensively in scientific research to solve mathematical problems. How Computers Work The physical computer and its components are known as hardware. Computer hardware includes the memory that stores data and instructions; the central processing unit (CP ....