$@: target, since it looks like a target.$<: the 1st prereq, since < points to the left.$^: all prereqs, since ^ looks like an "upward grouping flower bracket".$?: prereqs that are newer than the target, since ? is stuff you don't know / haven't looked at.$*: target with suffix deleted, since we generally grep for *.c|h|, we want the * part of $@.Alternatively, * is also like a target, but only the bull's eye with the extra stuff like the suffixstripped out.