Short answers, pulled from the story.
The word coat originates from a Proto-Indo-European root meaning woolen clothes, a linguistic thread stretching back thousands of years before the first garment was ever stitched. This ancient connection to wool reveals that the very concept of a coat was born from the human need to manipulate animal fibers for survival in cold climates.
In the early Middle Ages, the term coat carried a far more dangerous meaning than it does today, referring specifically to a coat of mail. By the medieval and Renaissance periods, the spelling shifted to cote or cotte, and the garment transformed into a mid-length, sleeved outer layer worn by both men and women.
Before the Industrial Revolution began in the second half of the eighteenth century, the extreme cost of cloth meant that certain styles of clothing were exclusive to the wealthy elite. The invention of the sewing machine in the nineteenth century, paired with existing textile machinery, shattered these barriers by increasing the affordability of mass-produced, ready-to-wear clothing.
The term jacket is a traditional term usually used to refer to a specific type of short under-coat, typically extending only to the upper thigh in length. Older coats such as tailcoats are usually of knee length, creating a clear visual distinction between the two garments.
The British Warm was designed for the British Army, while the Trench coat originated as a military garment for the trenches of World War I. The Parka, with its hood and heavy insulation, is a response to the harsh climates of the Arctic, while the Pea coat remains a staple of naval uniforms.