Branes are objects in M-theory and its offshoot, brane cosmology.

In M-theory, p-branes (the name is derived from membrane) are objects of spatial dimensionality p (for example, a string is a 1-brane). In brane cosmology, the term "brane" is used to refer to objects similar to our four-dimensional universe, which move in a higher-dimensional "bulk".

See also: P-branes, D-branes