A bayonet (from French baïonnette) is a knife, sword, or spike-shaped weapon designed to fit in, on, over or underneath the muzzle of a rifle, musket or similar weapon, turning the gun into a spear.
A halberd (also called halbard, halbert or Swiss voulge) is a two-handed pole weapon that came to prominent use during the 14th and 15th centuries. The word halberd may come from the German words Halm (staff), and Barte (axe). In modern-day German, the weapon is called a Hellebarde. The halberd consists of an axe blade topped with a spike mounted on a long shaft. It always has a hook or thorn on the back side of the axe blade for grappling mounted combatants. It is very similar to certain forms of the voulge in design and usage. The halberd was usually 1.5 to 1.8 metres (5 to 6 feet) long.
A Pike: A pike is a pole weapon, a very long thrusting spear formerly used extensively by infantry. Unlike many similar weapons, the pike is not intended to be thrown. Pikes were used regularly in European warfare from the early Middle Ages[1] until around 1700, and wielded by foot soldiers deployed in close quarters. The pike found extensive use with Landsknecht armies and Swiss mercenaries, who employed it as their main weapon and used it in pike square formations. A similar weapon, the sarissa, was also used by Alexander the Great's Macedonian phalanx infantry to great effect. Generally, a spear becomes a pike when it is long enough that it cannot be wielded with one hand in combat.