The term 'assimilation' again is in general use, being applied most often to the process whereby large numbers of migrants from Europe were absorbed into the American population during the 19th and the early part of the 20th century. The assimilation of immigrants was a dramatic and highly visible set of events and illustrates the process well. There are other types of assimilation, however, and there are aspects of the assimilation of European migrants that might be put in propositional form. First, assimilation is a two-way process. Second, assimilation of groups as well as individuals takes place. Third some assimilation probably occurs in all lasting interpersonal situations. Fourth, assimilation is often incomplete and creates adjustment problems for individuals. And, fifth, assimilation does not proceed equally rapidly and equally effectively in all inter-group situations.
According to Young and Mack, Assimilation is the fusion or blending of two previously distinct groups into one.
For Bogardus Assimilation is the social process whereby attitudes of many persons are united and thus develop into a united group.
Biesanz describes Assimilation is the social process whereby individuals or groups come to share the same sentiments and goals.
For Ogburh and Nimkoff; Assimilation is the process whereby individuals or groups once dissimilar become similar and identified in their interest and outlook.
Assimilation is a slow and a gradual process. It takes time. For example, immigrants take time to get assimilated with majority group. Assimilation is concerned with the absorption and incorporation of the culture by another.