The origin, invention, and introduction of the tank top is dated around 1945–50. It was during this time, after WWII that many new and innovative fabrics were being introduced to the American consumer. The development of new fabrics and materials which include nylon and rayon were a direct result of the war effort. After WWII, fashion and clothing designers began to introduce innovative new styles in apparel that included the newly developed materials. The development of the tank top can be directly traced to this time period. Tank tops were not only stylish apparel items, they were considered to be innovative fashion statements and an emerging clothing and dress accents. The tank top shirt or "pullover" has endured as fashion trends have changed and evolved. The changing fashion trends through the 60's, 70's, 80's, and even through to the 21st century have marked the "tank-top" as an enduring fashion and clothing item that is here to stay.

Tank tops come in a wide variety of colors, styles, and fabrics. There are feminine tank tops that accent many ladies ensembles and there are masculine tank tops which men find acceptable and stylish. The tank top can effectively be considered a "unisex" clothing item. The broad acceptance of the stylish shirt has secured it's place in the annals of fashion history and gained wide acceptance by men and women the world over. The tank top is manufactured and sold in clothing markets on all continents. The tank top is made in all sizes and is available for men, women, and children of all body types. In Europe and particularly the UK, the tank top can be described as a sleeveless sweater (tank top). The popular apparel item in also known as a sweater vest in North America and a "Langdon" in the Northeastern United States. The tank top sweater vest or "Langdon" is an item of knitwear that is similar to a sweater, but without sleeves. Langdon "tank-tops" were popular in the 20th century, particularly in the 1970's in the United Kingdom.

In order to understand the role of the tank top and pullover shirt in modern fashion, it is important to consider these facts about tank top development:

A tank top is a sleeveless shirt which is manufactured without sleeves, or one where the sleeves have been cut off. Tank tops are made in a wide variety of materials that include cotton, nylon, rayon, spandex, polyester, cotton-poly blends and more. Sleeveless shirts can be worn by either sex, depending on the style. These sleeveless shirts can also be undershirts and do not prevent sweat stains from showing through. In this respect, tank tops can be considered underwear, and in the case of women's apparel, even lingerie.

Tank tops are often worn by athletes in sports such as track and field and bicycling. Tank tops have been popular warm-weather casual wear in the United States in 1980's fashion trends, and are regarded as acceptable public casual dress in some locales. They are mostly preferred in hot climates, since the arm holes provide ventilation and the thin fabric provides comfort. Tank tops in the lingerie class (made from certain sheer, sexy fabrics) are not considered acceptable public apparel and are relegated to the lingerie class.

In American English, a tank top is a sleeveless T-shirt-like garment that can be worn by either sex. It is often worn under the shirt as underwear, although more colorful and well-designed tank tops are usually worn as an outer shirt. The term is also used in Australian English, although the term "singlet" is commonly used to refer to the garment. In British English, the term vest is used, while tank top refers to a sleeveless pullover. The name tank top, recorded in English since 1968, is derived from its resemblance to a tank suit, a style of one-piece women's swimsuit with shoulder straps. Its name derives from the 1920's term swimming tank, which is an obsolete term for what is now called a swimming pool. The "tankini" (a portmanteau of the words tank top and bikini) is a female swimming version of the tank top. The combination of the history, style, and technical terms applicable within the fashion industry is where the tank top gets it's name and classification.

The tank top is closely related to the "Halter" top in fashion design. A halter top is a sleeveless shirt in which a strap goes around the back of the neck, leaving the upper back uncovered. Halter tops are worn mainly by girls and women. The tank top is also closely related to the "Tube" top. A tube top is a shirt with no sleeves or shoulders, and is, basically, a tube that wraps around a woman's torso. In Great Britain and Australia, it is called a "boob tube". The tank top is somewhat different than the "tube top" or "halter top" and should not be confused with those items of apparel.

Another close relative to the tank