"cos" usually refers to the abbreviation of "China Airlines Co., Ltd." in Chinese mainland. It was founded in 1949 and is one of the earliest airlines in China. In addition, cos has other different interpretations. For example, in animation, games and other fields, cos refers to fan cultural activities such as costumes, props and makeup that play and copy a virtual character, which are often carried out in comic exhibitions, game exhibitions, theme parks and websites.

In computer science, "cos" refers to cosine function, which is one of trigonometric functions used to calculate cosine of any angle. Cosine function is widely used in mathematics and science, especially in signal processing, image processing, machine learning and other fields. In addition, "cos" is sometimes the abbreviation of "cosine oscillation", which means that the vibration signal oscillates with the cosine function as the period.

"cos" is widely used on Chinese Internet to refer to Tencent Cloud Open Service (COS), which is a cloud storage service provided by Tencent. COS can be conveniently used for file storage, CDN acceleration, data processing and other operations, providing users with efficient, stable and extensible file storage and transmission solutions. As one of the leading cloud computing service providers in China, the COS of Tencent Cloud has been widely used and recognized in various industries.