PASCAL Programming Fundamentals by P. S. Grover

A computert is a information processing machine. It can perform arithmetic opertions (addition, subtraction, multiplication and division) and take logical decisions. It has a memory and can store lot of information. The stored infirmation may be retrieved, moved and operated upon us desired. Computations are done at an extremaly fast speed with complete reability and accuracy. The speed of execution of operations by modern computers ranges from several hundred million operatuions per second for fast computers to tens of thousands of operations per second for slow computers.