A language is more than a means of communication: it is a unique reflection of the worldview held by the group of speakers; a vehicle of cultural expression and a depository of the value system of the speakers. It frames the identity of the speakers. Language is perhaps the most human of human traits. Who we are is essentially linked with the language or languages we speak. Language is essential to the well-being and continued progress of any human society. The survival of language is critical for our own survival. However, the world's linguistic diversity is being seriously threatened in the 21st Century by the rising tide of economic and cultural globalization and emerging technologies. According to the "UNESCO Atlas of World's Languages in Danger of Disappearing", among 6,000 languages that are spoken in our world today, nearly 43% are at risk of extinction.

Education systems play a critical role in whether languages become extinct- or are able to survive and thrive. On the other hand, shared languages and cultural references are the basis of knowledge transfer in the education system. However each day, millions of children are taught in languages which is not their own and hence must struggle to understand. Hence, UNESCO advocates the use of mother languages in school systems right from early years. Research supports that strong foundation in mother tongue is critical for cognitive development and it helps acquire other languages.

Proclaimed by the General Conference of UNESCO in November 1999, the International Mother Language Day has been celebrated every year on Feb 21 worldwide since 2000 to promote linguistic and cultural diversity and multilingualism. The theme of 2012 International Mother Language Day is "Mother Tongue Instruction and Inclusive Education". It highlights the importance of mother tongue from the angle of the right to education and encourages Member States to promote instruction and education in mother tongue.

The mother language or "mother tongue" is the language in which first words are spoken and thoughts expressed by an individual. Thus it is generally the language that a person speaks most fluently. Cognitively, the mother language is a crucial tool every child uses to understand the world. Culturally, the mother language is a fundamental expression of history and identity.

Often, the most disadvantaged people in a country are those whose mother language is different from the national language. This creates problems in many areas: education, health, income disparity, risk of exploitation, exposure to environmental hazards, access to the legal system, etc. Policies that take diversity of mother languages into account can help unite a country while strong monolingual policies can contribute to social division.

Governments and development organizations must take language into account when engaging people, rather than embracing a "one size fits all" language policy; as one slogan for the United Nations International Year of Languages declared: "Languages Matter!"

Languages matter for the fulfillment of the eight Millennium Development Goals (MDGs), adopted in 2000 by the General Assembly of the United Nations to eradicate extreme poverty and deprivation by 2015.