A unit vector is a vector that has a magnitude of exactly one. It is often used to indicate direction without considering the length of the vector. Unit vectors are typically represented with a hat notation, such as â or b̂, and can be derived from any non-zero vector by dividing the vector by its magnitude. Unit vectors are essential in various fields, including physics and engineering, as they help simplify calculations involving direction. They can be expressed in terms of the standard basis vectors i, j, and k in three-dimensional space, which correspond to the x, y, and z axes, respectively.