Basically "Informatics" and "Computer Science" are the same thing. In native English, the field is called "Computer Science", while in Spanish-influenced or French-influenced English, it might be called "Informatics", because "computer science" is "informática" and "informatique" respectively in those languages.
As to the difference between informatics/computer science and informatics/computer science engineering, I can't say for sure, but I suspect that the first has a more theoretical emphasis, while the second concentrates more on practical engineering-type applications. Maybe someone else can correct or elaborate on this.