Defensive Weapons

Lightsabers

Normally used by the Jedi, force users can use them to deflect blaster bolts. The jedi only use them for defense, but they can be used for offense if they fall into the wrong hands.

• 
  Lightsabers originally had to be powered via external powerpack, attached to the user's belt.
• 
  Lightsabers remained unchanged for millenia after an internal power was invented.
• 
  The next major breakthrough occurred not long before the Clone Wars: a new bit of technology which prevented the weapon from shorting out in water.
• 
  Jedi traditionally use blue or green crystals for their lightsabers, but their are exceptions, most notably Mace Windu's purple blade and weapons of padawans and other students.
• 
  The Jedi use 'training sabers' a low power version of the real ones. Even as young as three they used them for practice.
• 
  Sith usually use red lightsabers. Jedi rarely do. The red crystals are able to channel the dark side of the Force into the blade, as well as using the regular power supply.
• The Beam appears to be plasma based, a form of pure energy.

Ion Weapons

Ion weapons are capable of shorting out electronics, be they weapons, ships or droids. They can come as small as a pistol or large as a planetary cannon.

Stunner

Stunners do exactly that. They stun the target, leaving them dizzy and weak at least, unconscious at worse.

Energy Shield

An Energy shield prevents energy and rays from coming through it, such as blaster bolts or turbolaser fire. It can come in small personal use size to full scale planet size to prevent orbital bombardment. It does not affect projectiles, or solid matter from punching through.