Symbolic link Symlink
File system pointer — file A that "is" file B. Followed transparently by most programs.
Unix: ln -s target link. Windows: mklink. Different from a hard link (same inode). Classic uses: /usr/bin/python → python3, dotfiles management, Node.js node_modules. Security trap: "symlink attack" — create a symlink to trick a program into writing in the wrong place.