How to link to file one level above?

If you have a file which is in the root, and that file links to another file which is located in a folder, so you go to "/folder/file.html".

Now how would you do it the other way round? So to link to a file which is in the directory above you. I can't use the full url, so is there some symbol which represents "/" but in reverse?

If the path is: main/folder/file.html and file.html links to a document in "main" you would need to use ../ to access "main."

"../" goes one level above. It's UNIX-based folder structure:

/file.htm --> root directory/file.htm
./file.htm --> current directory/file.htm
../file.htm --> parent directory/file.htm

Hope this helps…