These laws define who is allowed to enter, stay, or work in the country and establish criteria for visas, permits, and residency requirements. 3. Border patrols and surveillance: Countries deploy border patrol agents and surveillance technologies, such as cameras, sensors, drones, and satellite imagery, to monitor border areas and detect irregular activities. Patrols may be conducted on foot, by vehicles, boats, or even aircraft. 4. Immigration and customs enforcement: Immigration and customs officers enforce immigration and customs laws at ports of entry and throughout the country.
