A script which tells the Unix program "make" how to build a particular computer program or set of programs. A makefile contains variable assignments and rules of the form
target: inputs commands
which say if any of the files in "inputs" has been modified more recently than file "target" (or if the target does not exist) then execute "commands", which will normally bulid "target" from "inputs".
If make is run with no arguments, it looks for a makefile called "Makefile" or "makefile".