The following explains Web Browsers and the process flow of Web applications, using CGI as the example.
CGI executes on the Web Server and is used for data input/output with Web Browsers. CGI is the most fundamental interface for executing CGI programs (called CGI scripts) on Web Servers from Web Browsers (clients). A request to the Web Server from a Web Browser provides the function of activating the CGI program and inputting/outputting the data (including the data input via environment variables).
CGI is executed in the processing flow of inputting the data (request), processing the data, and outputting the processing result (response), and the CGI program must be cognizant of this processing flow.
The processing flow by ISAPI and other APIs is basically the same as that of processing by CGI. However, CGI inputs/outputs the data via the standard input-output, and ISAPI or other APIs provide a special API (hidden in API) used for inputting/outputting the data. As this difference in data inputting/outputting between CGI and ISAPI or other APIs has been absorbed by the NetCOBOL Web subroutines, COBOL applications need not recognize this difference if the NetCOBOL Web subroutines are used.
