An automatic level is a professional leveling tool used in construction and surveying to measure horizontal distances accurately. There are different types of automatic levels suited to different jobs. To measure the distance between two points (A and B) using an automatic level, one sets up the level over point A and takes a reading, then shifts it to point B to take a second reading. The distance is calculated by multiplying the difference between the upper and lower readings by 100. For example, with an upper reading of 133.1 and lower reading of 122.8, the distance between points A and B is calculated as 10.3 meters. Automatic levels improve accuracy for tasks like grading and construction.