BY SEA (port to port): cheapest, volume unlimited but long sailing time, suits for bulk cargo and not urgent cargo.
BY AIR (airport to airport): fast, but expensive and volume restricted, suits for small valuable cargo and urgent cargo
BY EXPRESS (door to door): fast and easiest, wide-area coverage but expensive and volume & weight restricted, suits for small cargo and urgent, especially for sample.
BY RAILWAY: big volume, more expensive than by sea, tracking a little difficult, sometimes may delay, suit for big volume cargo in Central Asia.