Editor It accepts the typing of source code and header files. Source File The file that contains the program you prepare in the editor after saving it .cpp Header File It contains declarations for input and output streams.Header files such as iostream.h is used. Preprocessor It performs preliminary operations on file before passed to the compiler. Compiler It translates the source code into machine language. Object code A file contains the translated source code(.obj). Linker Links the object file with additional code such as library codes. Executable code A file contains the output(.exe) 1.3 Stream Stream is an inter-mediator between the I/O devices and the user. If data is received from input devices in sequence then it is called as source stream or input stream and when the data is passed to the output devices then it is called as destination stream or output stream. The input stream uses cin object to read data and the output stream uses cout object to display the data on the stream. The cin and cout are predefined stream for input and output data. The Predefined streams are cin:-Standard input, usually keyboard, corresponding to stdin in C. It handles input from input devices usually from keyboard. cout:-Standard output, usually screen corresponding to stdout in C.It passes data to output devices such as monitors and printers. Clog:-A fully buffered version of Cerror.It control error messages that are passed from buffered to the standard error device. Cerror:-Standard error output,usually screen corresponding to stderror in C.It controls the unbuffered output data.It catches the error and passes to standard error device monitor.