Cultural assimilation (often called merely assimilation) is a process of integration whereby members of an ethno-cultural community (such as immigrants, or ethnic minorities) are "absorbed" into another, generally larger, community. This implies the loss of the characteristics of the absorbed group, such as language, customs, ethnicity and self-identity.
Assimilation may be voluntary or forced, as is often the case regarding ethnic minorities (see forced assimilation).
A region or society where several different groups are spontaneously assimilated is sometimes referred to as a melting pot.
A group (a state or an ethnicity) can spontaneously adopt a different culture due to its political relevance, or to its perceived superiority. The first is the case of the Latin culture and language, that were gradually adopted by most of the subjugated people.
The second is the case of subjugated, but older and richer culture, which see itself imitated by the new masters, e.g. the victorious Roman Republic adopted more from the Hellenistic cultures than it imposed in most domains, except such Roman specialities as law and the military.