Branes, can essentially be considered to be point particles generalized to higher dimensions.
In string theory and supergravity, branes are physical objects, that essentially generalize the notion of a point particle to higher dimensions. Branes are dynamical objects. They can propagate through space according to the rules of quantum mechanics. Branes have mass and can have properties such as charge.
I now want to discuss the distinction between p-branes and D-branes.
p-branes
In zero dimensions, we have a point particle. In 1 dimension, we have a string. In 2 dimensions, we have a membrane. Indeed, you can consider higher dimensional branes. A p-dimensional brane is normally called a p-brane. The term "p-brane" was introduced by Michael Duff and others in 1988. The "brane" comes from "membrane." "Membrane" refers to a 2-dimensional brane. p-branes sweep out a (p+1)-dimensional volume in spacetime known as its worldvolume.
D-branes
In string theory, a string may be open or closed. D-branes become significant when one considers open strings. The end points of open strings are required to lay on the D-brane as they propagate through spacetime. The letter "D", in "D-brane", refers to the Dirichlet boundary condition that it satisfies.
The dynamics of a D-brane world volume is described by a gauge theory. Gauge theories are highly symmetric physical theories. They are also used to describe the behavior of subatomic particles in the Standard Model of particle physics. This relationship has led to insights in gauge theory and quantum field theory. An example of this is the AdS/CFT correspondence, where difficult problems in gauge theory are translated into easier calculations in string theory.