A more thorough explanation:

A sobriety test is a way to check if someone is drunk or under the influence of drugs. There are different types of sobriety tests, but they all aim to determine if a person is fit to drive or operate machinery.

• Coordination tests: These tests check a person's balance, reflexes, and coordination. For example, the police may ask someone to walk in a straight line or stand on one leg.
• Breathalyzer: This is a device that measures the amount of alcohol in a person's breath. The person blows into the device, and it gives a reading of their blood alcohol content (BAC).
• Horizontal-gaze nystagmus test: This test checks for involuntary eye movements that can occur when a person is drunk. The police may ask someone to follow a moving object with their eyes while keeping their head still.

These tests are used by law enforcement officers to determine if someone is too impaired to drive. If a person fails a sobriety test, they may be arrested for driving under the influence (DUI) or driving while intoxicated (DWI).

For example, if a person is pulled over for swerving on the road and smells like alcohol, the police may ask them to take a sobriety test. If the person fails the coordination test and breathalyzer, they may be arrested for DUI.