Parallel computing employs the use of multiple processors and specialized algorithms to solve problems.Using multiple processors has the potential to improve performance by dividing a task among several processors, thus reducing the amount of work each a processor, in turn reducing the time required to solve a problem.An overview of historical and modern parallel computer architectures will be given.Parallel computers are classified by their connection topology and control mechanisms. The recent development of multi-core machines has the potential to deliver inexpensive parallel computing.However, special algorithms must be developed that break a task into independent components. Because the number and speed of communication channels between processors influences performance, understanding how an algorithm affects communication of information among processors is critical in overall performance.Examples of sequential and parallel algorithms to solve several tasks will be presented to help illustrate these concepts.