Anglo is a prefix indicating a relation to the Angles, England, the English people, or the English language, such as in the term Anglo-Saxon language. It is often used alone, somewhat loosely, to refer to people of British Isles descent in the Americas, New Zealand, South Africa and Australia. It is also used, both in English-speaking and non-English-speaking countries, to refer to Anglophone people of other European origins.
Anglo is a Late Latin prefix used to denote English- in conjunction with another toponym or demonym. The word is derived from Anglia, the Latin name for England, and still used in the modern name for its eastern region, East Anglia. Anglia and England both mean land of the Angles, a Germanic people originating in the north German peninsula of Angeln, that is, the region of today's Lower Saxony that joins the Jutland Peninsula and thus forms an angle, so the Romans named it "Angulus".
It is also often used to refer to British in historical and other contexts after the Acts of Union 1707, for example such as in the Anglo-Dutch Treaty of 1824, where in later years agreement was between the British government and the Dutch, not an English government. Typical examples of this use are also shown below, where non-English people from the British Isles are described as being Anglo.