Old High German (OHG, German: Althochdeutsch, German abbr. Ahd.) is the earliest stage of the German language, conventionally covering the period from around 700 to 1050 AD. Coherent written texts do not appear until the second half of the 8th century, and some treat the period before 750 as "prehistoric" and date the start of Old High German proper to 750 for this reason. There are, however, a number of Elder Futhark inscriptions dating to the 6th century (notably the Pforzen buckle), as well as single words and many names found in Latin texts predating the 8th century.
The main difference between Old High German and the West Germanic dialects from which it developed is that it underwent the Second Sound Shift or High German consonant shift. This is generally dated approximately to the late 5th and early 6th centuries—hence dating its start to around 500 AD. The result of this sound change is that the consonantal system of German remains different from all other West Germanic languages, including English and Low German. Grammatically, however, Old High German remained very similar to Old English, Old Dutch, and Old Saxon.
German (Deutsch [ˈdɔʏtʃ]) is a West Germanic language that derives most of its vocabulary from the Germanic branch of the Indo-European language family. A portion of German words are derived from Latin and Greek, and fewer are borrowed from French and English. Languages which are most similar to German include Afrikaans, Dutch, English, the Frisian languages, the continental Scandinavian languages and Luxembourgish. A Germanophone is a speaker of the German language either natively or by preference.
German is the most widely spoken (and official) language in Germany, Austria, Switzerland, the Italian province of South Tyrol (Italian: Alto Adige) and Liechtenstein; it is also an official, but not majority language of Belgium and Luxembourg. With slightly different standardized variants (German, Austrian, and Swiss Standard German), German is a pluricentric language. German is also notable for its broad spectrum of dialects, with many unique varieties existing in Europe and also other parts of the world. Due to the limited intelligibility between certain varieties and Standard German, as well as the lack of an undisputed, scientific difference between a "dialect" and a "language", some German varieties or dialect groups (e.g. Low German/Plautdietsch) are alternatively referred to as "languages" and "dialects".
The High German languages or High German dialects (German: Hochdeutsche Dialekte) comprise the varieties of German spoken south of the Benrath and Uerdingen isoglosses in central and southern Germany, Austria, Liechtenstein, Switzerland, and Luxembourg as well as in neighboring portions of Belgium (Eupen-Malmedy) and the Netherlands (Southeast Limburg), France (Alsace and northern Lorraine), Italy (South Tyrol), and Poland (Upper Silesia). They are also spoken in diaspora in Romania, Russia, the United States, Brazil, Argentina, Mexico, Chile, and Namibia.
The High German languages are marked by the High German consonant shift, separating them from Low German and Low Franconian (Dutch) within the continental West Germanic dialect continuum.
As a technical term, the "high" in High German is a geographical reference to the group of dialects that forms "High German" (i.e. "Highland" German), out of which developed Standard German, Yiddish and Luxembourgish. It refers to the Central Uplands (Mittelgebirge) and Alpine areas of central and southern Germany, it also includes Luxembourg, Austria, Liechtenstein and most of Switzerland. This is opposed to Low German, which is spoken on the lowlands and along the flat sea coasts of the North German Plain.