U5

U5 is a designation used in several contexts to label the fifth item in a series that begins with U. The most prominent use is in public transportation: U5 denotes a line of the Berlin U-Bahn in Germany. The U5 line runs from Hönow in the eastern outskirts to Alexanderplatz in central Berlin and is operated by Berliner Verkehrsbetriebe (BVG). It serves many neighborhoods and intersects with several other U-Bahn and S-Bahn lines, forming an important east–west corridor in the city.

In naval history, U5 or U-5 has been used as a hull number for German submarines in the early 20th century and in other periods when the prefix U was applied to underwater craft. References to U-5 appear in discussions of submarine design and wartime operations, reflecting the broader use of the designation for underwater vessels.

In technology and consumer products, U5 can also appear as a model or version code indicating the fifth generation or revision within a product line. Such usage is common across electronics, automotive, and other industries, where U5 signals a specific iteration rather than a single standardized meaning.

Because U5 appears in multiple fields, its precise meaning depends on the context. When encountering the term, it is helpful to consider the domain (transport, naval history, technology, etc.) to determine which U5 is being referenced.