Computer is a wonder of modern science. The present world is called the computer word. Science is now the driving force of modern civilization. Science has entered everywhere. There are so many inventions which are serving in respective files. Computer is invented by the hard work of many scientists. Charles bavez is called the father of modern Computer at first in 1833. His invented computer had five parts. There were store, mill, control input and output. By following the structure of computer of bavez, Harvard invented an IBM computer in 1944. After this, it has been rapidly modified and many other computers have been invented. A computer performs three functions. It receives data. At first the details of work are put in the input of the computer. It is called programme. The computer does not work in our language. So the programme is to put in its own language. This programme is typed and produced in the tele +/pe unit of the results with the help of printing machine. Its signal goes to the memory and the control unit reads to the arithmetic unit. After finishing its tasks it, sends them to the result of output. Thus result is emitted by computer. Computer is very useful for us. It we used in our daily life of various purpose. Computer has made a great change in education. The students of developed countries use computer prepare their study materials. The result of various examinations is prepared accurately by computer within a short time. Besides printing thousands of books are made within a short time, computer contribute a lot in education. At present computer is used to diagnose disease. A new process of operation is invented by computer an alternative of surrey. Beside this, computer is used to grind stones in normal pathological test. Science should be meant for the service of humanity computer is the greatest contribution of science. It is expected to render the greatest service of humanity by substituting human brain. I think this computer can help Bangladesh to solve many unsolved problems. So, this is one of the wonders of modern science.