Assault with a deadly weapon is when a person causes another person to have a legitimate belief that harm—and potentially deadly harm—is imminent, by intimidating the person with a deadly weapon. No physical contact is necessary for assault with a deadly weapon to take place. There just has to be the intimidation and implied threat of harm with a deadly weapon.
There are many different types of weapons that can be viewed as deadly. Guns, knives and swords are examples. An example of assault with a deadly weapon would be a person holding a knife to another person's throat, without actually touching their throat or doing any physical harm. Assault with a deadly weapon is a very serious criminal offense and can be punished severely. If any physical harm is actually done, then battery charges can accompany the assault charges, and the punishment can be even worse.