Mechanized infantry or "mech infantry" (not to be confused with the later walkers, or war droids, which sometimes were also referred to as "mechas") was primarily devised as a mean to transport infantry at the same pace as tanks, regardless of the terrain. At the beginning they were mostly half-tracked or all-wheeled, with later designs leaning towards full-tracked vehicles. Mechanized infantry not only was able to cover rough terrain more quickly than motorized (or traditional) infantry, but also had much better protection from enemy fire, including biological, chemical, and nuclear weapons.