A path separator is a character used in file systems to distinguish between different levels of directories or folders in a file path. In most operating systems, the path separator is a forward slash (/) for Unix-based systems like Linux and macOS, while Windows uses a backslash (\). This character helps the system understand the hierarchy of files and directories. When specifying a file location, the path separator allows users to navigate through the directory structure. For example, in the path C:\Users\Documents\File.txt, the backslashes indicate that "Users" is a subdirectory of "C:", and "Documents" is a subdirectory of "Users."