A cardigan sweater is usually open and buttoned; the tied garment is considered a robe. A knitted garment with a zipper can also be called a cardigan. The current trend is for garments to have no buttons or zippers and are designed to hang open. In contrast, pullovers do not open in the front, but must be "pulled" over the head to be worn. Cardigan sweaters can be machine knitted or hand knitted. Traditionally, cardigan sweaters, as long as they were made of wool, can now be made from cotton, synthetic fibers or a combination of other materials.
There is also a little story about the cardigan sweater, named after James Brudenell, 7th Earl of Cardigan, a British Army major general who led the Battle of Balaclava during the Crimean War Light brigade charge. It was modeled after the knitted wool vest worn by British officers during the war. Legends of the incident and the fame Lord Cardigan gained after the war led to the dress's rise in popularity - it is said that Brudnell was accidentally caught in the fireplace after noticing the tail of his coat Invented this cardigan after burning it.
Cardigan sweaters originally referred to mainly knitted sleeveless vests, but have expanded to other types of clothing over time. Plain cardigans are often worn under shirts and blazers as a less formal version of a vest or tank top that restricts a tie when the jacket is removed. Its versatility means it can be worn casual or formal in any season, but is most popular in cooler weather.
A monochromatic cardigan, in sleeve or vest form, might be seen as a conservative fashion staple. As formal wear of any gender, it is worn over a button-down dress shirt. A less formal style is to wear a t-shirt underneath.