This basically involves checking whether a file with the given path exists or not. This can help us write fail-safe code in such a way that we read a file only after establishing that it exists in the given path:

string file = "C:\UCN Code Base\Programming-in-C-Exam-70-483-MCSD-Guide\Book70483Samples\Chapter 20\IO Operations.txt";
if(File.Exists(file))
{
     Console.WriteLine("File Exists in the mentioned path");
}
else
{
     Console.WriteLine("File does not exists in the mentioned path");
}

File is a static class available in the System.IO namespace. This class provides operations that we can use to execute functionalities related to file access. In the preceding code, we have declared a file path and, using the static File class, we are checking whether the file indeed exists in the given path.