Oil dipsticks as tiny as they are have very important function in a car. They are used for checking the oil levels. In a car, there are engine oil and transmission oil dipsticks.
Not all cars (especially modern cars) have dipsticks. They have oil level sensors or have different procedure for checking oil level without the use of dipsticks.
Similarities between engine and transmission oil dipsticks
Both of them are used for checking the level of oil. For both, a level below the lower mark of the dipstick indicates an underfill while a level above the upper mark indicates an overfill. A level just before or at the maximum mark is good.
How to read an engine oil dipstick
These are the procedures for checking the engine oil level with the use of an engine oil dipstick:
1. When engine oil has settled in the sump after the vehicle has been parked for some time (preferably in the morning, before starting the car), remove the engine oil dipstick and wipe it clean of the engine oil on it.
2. Dip the stick into the dipstick pipe again then pull it out. Keep holding it in that same vertical position.