It's often used in:
* Maps and directions: "Take exit 12, then go 3 mi east."
* Road signs: "Speed limit: 55 mi/h"
* Vehicle odometers: "Distance traveled: 100 mi"
However, "mi" can also have other meanings depending on the context, such as:
* Military Intelligence: In the military, "MI" stands for Military Intelligence.
* Machine Intelligence: In computer science, "MI" sometimes refers to Machine Intelligence.
To determine the correct meaning, you need to consider the surrounding text and context.