Samurai used to be the name that referred to all trained warriors in the Japanese army and followed Bushido, or the Samurai ethic code. They fought the country's battles as well as defended the daimyo, or local lords. The Samurai became local lords and nobility themselves, though they were divided in two diferent groups: the kasoku and the shizoku, the latter being the gentry.
The Samurai were masters of weapons, and were very experianced fighters. Specifically, they used bows, spears, and swords, and eventually guns. In many troops they replaced their spears and bows with guns, in fact. But there were still some elite troops that maintaned archers. Guns had too many advantages (i.e. range, efficiency, and reload time) to exclude.
In ways of defense, the Samurai were loaded. They had armor calld "do" that hung off their shoulders, and sometimes deflected bullets very well. However, this armor, called temeshi gosuku, was very expensive, and only used by the higher classes. Jingasa was their war hat, a pointed metal or leather cap. There was another kind of hat called a hachimaki, which probably gives the least amount of protection. It is made of chain mail sewn onto a band. Shin (Suneate) and thigh (haidate) guards, armored sleeves (kote), and face masks (mempo) complete their armor. Many times, on the back of their do, they carried a family crest or a personal banner.
But that is enough about Samurai. They are not nearly as cool as the Ninjas.