Key difference: Jackets are a hip- or waist-length garment used as a covering over clothes. A coat is warm piece of clothing that is thigh- or knee- length, and is worn in cold weather.

The terms jackets and coats have become synonymous in many places especially with the introduction of newer fashions that confuse or overlap the terms. Traditionally, the term jackets referred to a garment that is waist-length or hip-length. A coat, on the other hand, is a long piece of clothing that either thigh- length or knee-length, and is typically worn in cold weather.

A jacket is a hip- or waist-length garment with sleeves that fastens in the front, usually by means of buttons or zippers. It is meant as a covering for the upper body. It is usually lighter, tighter-fitting, and less insulating than a coat. The term jacket comes from the French noun jaquet, which refers to a small or lightweight tunic.

A coat is a garment that is typically used for warmth. They have long sleeves and fasten in the front by means of buttons, zippers, hook-and-loop fasteners, toggles, a belt, or a combination of these. They are usually long in length, often ending at thigh-length or knee-length, and at times even at ankle-length. The early use of coat in English was a coat of mail, meaning chain mail, which usually protected the wearer from weapons. However, nowadays a coat only protects from cold weather.

In addition, they can also be differentiated by claiming that a jacket is something like a thin coat worn in slightly coat weather, while a coat is thicker and meant for colder weather. However, there are some exceptions to this case, e.g. a ski jacket, which is warmer that a coat.

In modern terminology, jackets and coats have become synonymous, especially in American English, in which they are used interchangeably. Nowadays, jackets are used fashionably more often than that as protective clothing. Coats are mainly still used as protective clothing. Many even wear jackets as a fashion, over which they wear a coat, while steeping out.

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