File name

A file name is the part of the complete filename which contains the actual title of the file. For example "index.html" has the filename "index" (NEVER "index."), it is the whole name of the file before the dot that precedes the file extension.

Certain filenames are like this "very.nice.filename.txt", and most operating systems are capable of detecting the file name properly. The way to do this is to consider every dot before the final dot as part of the file name and not the extension, only the final dot and what is after it is considered to be the file extension.