At least 60% of a boxer's punches will be straight jabs. It's the busiest punch in boxing because it can be thrown quickly without compromising a boxer's defense. In a boxing match the jab is utilized to score, keep your opponents at bay, and to set up combinations and power punches.
Remember all punches should be executed from a balanced boxing stance.
1 - The same arm as the lead foot extends forward, with the fist rotating so that the palm is parallel to the floor. Keep your elbows tucked in.
2 - The arm is brought back as quickly as it is thrown forward.
3 - Care has to be taken not to hyperextend at the elbow joint.
Jabs should be delivered directly from the chin with no wind-up. All punches should be "snapped" - Sharp delivery and sharp recovery.