What do we measure by odometer installed in vehicles?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Odometer**: The odometer is a device installed in vehicles that measures the distance traveled by the vehicle. It is an essential instrument for tracking how far a vehicle has gone since its last reset or since it was manufactured.

2. **Function of the Odometer**: The primary function of the odometer is to provide a cumulative total of the distance the vehicle has traveled. This information is crucial for various reasons, including maintenance schedules, fuel efficiency calculations, and determining the overall wear and tear of the vehicle.

3. **Odometer vs. Speedometer**: It is important to differentiate between the odometer and the speedometer. While the odometer measures total distance traveled, the speedometer indicates the instantaneous speed of the vehicle at any given moment.

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