the use is to distinguish a vector with same magnitude but different position ..
 
						

							
Unit vector is used to find the product of any two vector quantities!!!!!!!!...
						

							
Dear Akhtar,
Unit vector:A Vector having magnitude ''1''and it has some specific direction is called a unit vector.
use of unit vector:A unit vector is used to specify the direction of a vector and it is not disturb the magnitude of any vector because its magnitude is one.
						

							
In mathematics, a unit vector in a normed vector space is a vector (often a spatial vector) whose length is 1 (the unit length). A unit vector is often denoted by a lowercase letter with a "hat", like this:  (pronounced "i-hat").
In Euclidean space, the dot product of two unit vectors is simply the cosine of the angle between them. This follows from the formula for the dot product, since the lengths are both 1.
The normalized vector or versor  of a non-zero vector u is the unit vector codirectional with u, i.e.,


where ||u|| is the norm (or length) of u. The term normalized vector is sometimes used as a synonym for unit vector.
The elements of a basis are usually chosen to be unit vectors. Every vector in the space may be  written as a linear combination of unit vectors. The most commonly  encountered bases are Cartesian, polar, and spherical coordinates. Each uses different unit vectors according to the symmetry  of the coordinate system. Since these systems are encountered in so  many different contexts, it is not uncommon to encounter different  naming conventions than those used here.