Simply type make from command line.
UNIX automatically looks for a file called Makefile (note: capital M rest lower case letters).
So if we have a file called Makefile and we type make from command line. The Makefile in our current directory will get executed.
We can override this search for a file by typing make -f make_filename
e.g. ~ make -f my_make
There are a few more -options for makefiles - see manual pages.