Final answer:
An orange level on the Department of Homeland Security's advisory system indicates a High risk of terrorist attacks, which requires increased security measures.
Step-by-step explanation:
The orange level on the Department of Homeland Security's daily advisory system indicates a High: High risk of terrorist attacks. This color-coded advisory system is designed to inform the public about the likelihood of a terrorist threat. An orange level suggests significant risk, but not the highest level of threat which would be indicated by red, meaning "Severe: Severe risk of terrorist attacks." Therefore, when the advisory level is orange, the government has identified a greater likelihood of a terrorist act occurring, calling for increased security measures and vigilance among law enforcement agencies and the public.