Cantonese is a language spoken throughout China and some neighboring countries. It is classified variously as both a dialect of Chinese, and as a language in its own right. Cantonese is often also referred to as Yue. It is spoken by between 50 and 80 million people, although exact numbers are difficult to determine because of its relationship to other Chinese dialects.

Cantonese is mostly spoken in south east China, and related regions such as Hong Kong and Macau. Outside of China it has major population bases in Indonesia, Malaysia, the Philippines, Singapore, and Thailand.

Since the Qin dynasty, the area in which Cantonese is now spoken began to be settled by Han Chinese. The Chinese language as a result began to assimilate and supplant local languages. During the Sui dynasty the influx of Han Chinese increased immensely, and the language gained even more hold. At the same time, the language began to exhibit differences from the Chinese spoken in central China. During the Tang dynasty Cantonese returned to being more similar to central Chinese, but immediately afterwards, in the Song dynasty, it split even further.

Through the Yuan, Ming, and Qing dynasties, Cantonese continued to develop its own idiosyncrasies, and to separate even further from central Chinese. Near the end of the Qing dynasty, most of China was closed to trade with the West. One notable exception was Guangzhou, where Cantonese was widely spoken. As a result, many Westerners learned Cantonese, and it began to gain more traction in the government. When Western powers took control of Hong Kong and Macau, where Cantonese was the primary language, it gained even more credibility in the West.

In the modern world, Mandarin Chinese remains the official language for all of China. As a result, most official documents and educational texts are in Mandarin. Cantonese, however, remains widely used for social and everyday communications in south east China. In Hong Kong, unlike the mainland, Cantonese is used as the de facto official language, and so is prevalent in all aspects of society.

Although considered a dialect of Chinese by some people, Cantonese is largely unintelligible to speakers of Mandarin. Originally Cantonese had no written form, and instead used the writing of Standard Chinese, which is essentially Mandarin in written form. Over time, however, the need for a distinct written form became apparent, as Standard Chinese became less and less suited to meet the needs of spoken Cantonese.

Eventually, in the 19th century, Cantonese began to appear as its own distinct written form. Today, Cantonese may be written in two different modes: formal and colloquial. Formal written Cantonese shares a great deal of similarities with Standard Chinese, and can generally be understood by speakers of Mandarin with a bit of effort. Colloquial written Cantonese is unintelligible to speakers of Mandarin, but better reflects the nuances of spoken Cantonese. Colloquial written Cantonese is used for personal writing, poetry, magazines, diaries, and to a limited extend for distinctly Cantonese literature.