Make

In software development, Make is a utility that automatically builds executable programs and libraries from source code by reading files called makefiles which specify how to derive the target program. Though integrated development environments and language-specific compiler features can also be used to manage a build process, Make remains widely used, especially in Unix.

Behavior

Make is typically used to build executable programs and libraries from source code. Generally though, any process that involves transforming a source file to a target result (by executing arbitrary commands) is applicable to Make. For example, Make could be used to detect a change made to an image file (the source) and the transformation actions might be to convert the file to some specific format, copy the result into a content management system, and then send e-mail to a predefined set of users that the above actions were performed.
Make is invoked with a list of target file names to build as command-line arguments:
    make TARGET [TARGET ...]

Makefiles

Make searches the current directory for the makefile to use, e.g. GNU make searches files in order for a file named one of GNUmakefile, makefile, Makefile and then runs the specified (or default) target(s) from (only) that file.

The makefile language is similar to declarative programming. This class of language, in which necessary end conditions are described but the order in which actions are to be taken is not important, is sometimes confusing to programmers used to imperative programming.

References

http://www.openbsd.org/cgi-bin/man.cgi?query=make#FILES
http://en.wikipedia.org/wiki/O%27Reilly_Media