The libpng-devel package contains libraries and header files for developing applications that using the PNG library.
acquired package info from repodata DB: repodata/bbb184c59d147ac8008bfc4e65cc222611fcbe5e39579873511151bfe6007f20-primary.sqlite.bz2
The libpng-static package contains the statically linkable version of libpng. Linking to static libraries is discouraged for most applications, but it is necessary for some boot packages.