Foot

Definition: A foot (symbol: ft) is a unit of length in the imperial and US customary systems of measurement. A foot was defined as exactly 0.3048 meters in 1959. One foot contains 12 inches, and one yard is comprised of three feet.
Current use: The foot is primarily used in the United States, Canada, and the United Kingdom for many everyday applications. In the US, feet and inches are commonly used to measure height, shorter distances, field length (sometimes in the form of yards), etc. Feet are also commonly used to measure altitude (aviation) as well as elevation (such as that of a mountain). The international foot corresponds to human feet with shoe size 13 (UK), 14 (US male), 15.5 (US female), or 46 (EU).
Mile

Definition: A mile (symbol: mi or m) is a unit of length in the imperial and US customary systems of measurement. It is currently defined as 5,280 feet, 1,760 yards, or exactly 1,609.344 meters.
Current use: Although most countries have adopted the metric system and use kilometers, rather than miles, to express land distance, the mile is still prevalently used in countries such as the United States (US), United Kingdom (UK), Myanmar, and Liberia, as well as some other countries which are either US or UK territories, or have historical ties with either country.

Historically, the human body(foot) was used as the basis for measurement and inch is referred to the width of a man's thumb,the miles a British imperial measure and a customary unit of distance in the United States,to convert from Feet to miles  you can divide it by 5280, because there are 5280 feet in a mile.
And  1 inch is equal to 1/12 for convert feet to inches or use a much simpler way through the website :https://www.calculatorful.com/feet-to-inches