Nationalism is an ideology that emphasizes the importance of the nation-state and the individuals loyalty and devotion to it, often surpassing other individual or group interests. It aims to build and maintain a single national identity based on shared social characteristics such as culture, ethnicity, geographic location, language, politics, religion, traditions, and belief in a shared singular history, and to promote national unity or solidarity. Nationalism seeks to preserve and foster a nations traditional culture and has been associated with movements for freedom and justice, cultural revivals, and pride in national achievements. However, it has also been used to legitimize racial, ethnic, and religious divisions, suppress or attack minorities, and undermine human rights and democratic traditions.

There are various definitions of a "nation," which leads to different types of nationalism. Nationalism is a modern movement that began to be a generally recognized sentiment molding public and private life and one of the great, if not the greatest, single determining factors of modern history. The sociological or modernist interpretation of nationalism and nation-building argues that nationalism arises and flourishes in modern societies that have an industrial economy capable of self-sustainability, a central supreme authority capable of maintaining authority and unity, and a centralized language understood by a community of people.

Historically, the concept of nationalism has been divided between "civic" and "ethnic" nationalism. Civic nationalism is grounded in inclusionary values of freedom, tolerance, and equality, while ethnic nationalism comprises an eclectic mix of ideology, combining both racial and cultural nationalist thinking. Benedict Anderson defines the nation as "an imagined political community – that is culturally imagined as both inherently limited and sovereign". There are four key elements to this definition: the nation is imagined, limited, sovereign, and predicated on an identification of "non-nationals" and exterior threats to the nation.

In summary, nationalism is an ideology that emphasizes the importance of the nation-state and the individuals loyalty and devotion to it, often surpassing other individual or group interests. It seeks to build and maintain a single national identity based on shared social characteristics and promote national unity or solidarity. Nationalism has been associated with movements for freedom and justice, cultural revivals, and pride in national achievements, but it has also been used to legitimize racial, ethnic, and religious divisions, suppress or attack minorities, and undermine human rights and democratic traditions.