When describing this character, label it as backslash (\) for clarity.
Do not use a backslash in internet addresses (use a forward slash).
Use a backslash in file paths for Windows systems only. Use a forward slash for MacOS and UNIX/Linux paths.
Do
Download from ftp://example.com/downloads.
MacOS: Save to the /Users/your-name folder.
Windows: Save to C:\catalog\collect.doc.
Don't
Download from ftp:\\example.com\downloads.