The term 城镇 is deeply intertwined with the story of modern China. For the past four decades, China has undergone the largest and fastest urbanization process in human history. 城镇 is the linguistic symbol of this massive societal shift. It's one half of a critical socio-economic concept: the urban-rural divide (城乡差别 - chéngxiāng chābié). In this context, 城镇 represents modernity, economic opportunity, higher education, and a faster pace of life. It stands in contrast to the 农村 (nóngcūn - countryside), which is often associated with tradition, agriculture, and a slower lifestyle. The mass migration of hundreds of millions of people from the 农村 to the 城镇 in search of work and a better life has fundamentally reshaped Chinese society. While in the West we might use “urban areas” in a dry, demographic sense, in China, 城镇 carries the weight of national policy, personal aspiration, and dramatic social change. It's a key term in discussions about “urbanization” (城镇化 - chéngzhèn huà), a central goal of the Chinese government's development plans.
城镇 is more common in formal, written, or abstract contexts than in casual, everyday speech about one's own location.