What are the stream files?

We can open file in C with using stream files.which are identified with a pointer to a FILE structure, or as low-level files, which are identified with an integer handle. We can open stream files with using one of the following functions.

fopen(): Opens the specified file with the specified mode 

freopen(): Closes the file specified, then opens a new file as specified 

fdopen(): Opens a duplicate stream file for an already open low-level file