What is the difference between “Brüder” and “Gebrüder”?

„Brüder“ is the plural of „Bruder“ (like brothers -> brother)

„Gebrüder“ means ALL brothers of a family.

Source: http://www.duden.de/rechtschreibung/Gebrueder

Gebrüder oder Brüder? Während Brüder lediglich die Mehrzahl bezeichnet, bezieht sich Gebrüder auf die Gesamtheit der Brüder einer Familie (dieser Sprachgebrauch ist allerdings veraltet) beziehungsweise auf Brüder, die gemeinsam ein Unternehmen leiten. Es heißt im Übrigen richtig »die Brüder (nicht: Gebrüder) Grimm«, denn Jacob und Wilhelm Grimm waren die beiden ältesten von fünf Brüdern und nannten sich selbst nur Brüder Grimm.

In current usage, „Gebrüder“ is next to never used casually. It“s used in religious or otherwise ceremonial contexts (where it can well designate more than literal brothers), or in company names. For example, Adidas and Puma started out as „Sportschuhfabrik Gebrüder Dassler“. In this comment a Swiss business founder asks about legal details about his planned company name that contains „Gebrüder“.

To answer the 2nd part of your question – the prefix Ge- can express an affiliation or shared identity and also appears in a similar sense in the words Geschwister (siblings), Gesamtheit (totality), Genosse (comrade), etc

https://de.wiktionary.org/wiki/ge-

Gebrüder is an old styled language use. You“ll find it in older storybooks from the 19th century or early 20th century.

Comments

• While it is true that Gebrüder is veraltet according to Duden, there is still a difference in the two words’ meanings that this answer fails to address.

Brüder is simply the plural form. Gebrüder is more an indication of association and like mindedness, a grouping. Afrikaans, which is a derivative of Dutch, German and French mostly, has similar forms. The meaning in Afrikaans is now understood by nuance and form of expression.

Comments

• Gebrüder is not an indication of association and like-mindedness.