Most English-speakers have three names, e.g.,John David Smith.Smith is his family name, which he inherits from his father, and the other two are personal given names that his parents chose when he was born.By u201cfirst nameu201d they mean the given name, which in the example above is u201cJohnu201d.By u201clast nameu201d they mean family name or surname, which in the example above is u201cSmithu201d.Many forms do not want the middle name, u201cDavidu201d, which is only used in very formal situations. So that would be omitted in two-name situations, he would just write u201cJohn Smithu201d.If it happened that this person disliked the name u201cJohnu201d, he might ask his friends to call him u201cDavidu201d instead. In that case, he would write u201cDavid Smithu201d on his form and only use u201cJohnu201d in formal situations.It might be that the middle part of your name is a patronymic, i.e., a reference to your father.Ivan Petrovich SmirnovIn that case, you would only write u201cIvan Smirnovu201d and leave out the u201cPetrovichu201d.It might be that in your culture you write the family name first and use a generational name, e.g.,Chang Han Wei.In that case, write u201cChangu201d for last name and u201cWeiu201d for first name. Omit the generational name, as this is not a custom among English-speakers.