Mulatto is a term used to refer to people born of one white parent and one black parent or to people born of a mulatto parent or parents.
In English, the term is today generally confined to historical contexts.
Muwallad literally means "born, begotten, produced, generated; brought up", with the implication of being born and raised among Arabs, but not of Arab blood.
According to the same source, the term does not denote being of mixed-race but rather being of foreign-blood and local culture.
In English, printed usage of mulatto dates to at least the 16th century.
The persistence of some authors to use this term out of historic context reflects the old-school essentialist views of race as a de facto biological phenomenon and the 'mixing' of race as legitimate grounds for the creation of a 'new race'.
This is in disregard of cultural, linguistic and ethnic diversity and/or differences between regions and globally in populations of mixed ancestry.