The YouTube video titled "How to Count Line, Words and Characters of a File in Linux" demonstrates how to use the WC command to determine the number of lines, words, and characters in a file. By opening the terminal and typing "wc" followed by the file name, the output will display the total count for each category. To view only the number of lines, use "wc -l"; for words, use "wc -w"; and for characters, use "wc -c." The presenter adds that you can combine these options, such as "wc -l -w -c filename," to display all three counts in a single command.