Bilingual teaching, that is, teaching some or all non-linguistic subjects in a non-native language, has different practical connotations in different countries and regions. For example, in Canada, bilingual teaching generally refers to the form of teaching in French in English-speaking areas. In the United States, bilingual teaching generally refers to the subject teaching of Spanish. In Australia, bilingual teaching refers to teaching certain subjects in a non-native language (English). Most of its purpose is to make these countries with many immigrants better reflect their diversity and integration. In Europe, the situation of bilingual teaching is more complicated, and most of the languages involved are English, aiming at strengthening exchanges between countries, prospering the economy and forming a joint force. Bilingual teaching, which is being explored and experimented in China and many Asian countries and regions, generally refers to the system of teaching subjects in English. Therefore, the connotation of bilingual teaching, which began to be popularized in the experiment, should also belong to this category. The basic requirement of bilingual education generally accepted in the world is to use two languages as teaching media in a planned and systematic way in the process of education, so that students can achieve smooth and natural development in the overall knowledge, bilingual ability and cultural learning and growth represented by these two languages. Here, the second language is the language and means of teaching, not the content or subject of teaching.

In China, bilingual teaching refers to the use of a foreign language as the main language except Chinese, mainly English. Correct and fluent English is needed to explain knowledge, but Chinese is not absolutely excluded to avoid students' thinking obstacles caused by language lag; Teachers should use nonverbal behavior to prompt and help students understand the teaching content intuitively and vividly, thus reducing the difficulty of students' English understanding. Unlike Singapore, Canada and India, China is a bilingual country with unequal language environment. Therefore, the bilingual teaching environment in China determines its purpose, which belongs to the category of "foreign language" teaching, not "second language" teaching. Bilingual teaching in China can only be "maintenance bilingual teaching" in the above definition.

The "benefits" of bilingual teaching are twofold: one is to acquire subject knowledge, and the other is to cultivate and improve students' ability to use foreign languages.