Siege means that the enemy would camp around the castle until they fled so that they could take over the castle they would also attack the castle until it was almost destroyed and wait out until the enemy castle ran out of food or until they all got sick and all died.
A ballista is a catapult in the middle ages for launching rocks at enemy castles and for penetrating highly killers in the battle field.
The ballista was made of wood,stone,long thin ropes and bendable thin pieces of wood.It also has a pouch,capstan,drawstring,winch a skien and a swing arin.
This is a map out of the tools used for the ballista
Well I hope you liked this presentation on the ballista. also hope you learned a lot about the ballista.