The two parts of install

Automake generates separate install-data and install-exec targets, in case the installer is installing on multiple machines which share directory structure--these targets allow the machine-independent parts to be installed only once. install-exec installs platform-dependent files, and install-data installs platform-independent files. The install target depends on both of these targets. While Automake tries to automatically segregate objects into the correct category, the Makefile.am author is, in the end, responsible for making sure this is done correctly. Variables using the standard directory prefixes data, info, man, include, oldinclude, pkgdata, or pkginclude (e.g. data_DATA) are installed by install-data.

Variables using the standard directory prefixes bin, sbin, libexec, sysconf, localstate, lib, or pkglib (e.g. bin_PROGRAMS) are installed by install-exec.

Any variable using a user-defined directory prefix with exec in the name (e.g. myexecbin_PROGRAMS is installed by install-exec. All other user-defined prefixes are installed by install-data.