About Communications

The file input and output (I/O) functions (CreateFile, CloseHandle, ReadFile, ReadFileEx, WriteFile, and WriteFileEx) provide the basic interface for opening and closing a communications resource handle and for performing read and write operations. The Microsoft® Win32® API also includes a set of communications functions that provide access to communications resources. This overview describes the use of file I/O and communications functions, which enable applications to perform the following tasks: