A Euclidean vector is a geometric object that represents both direction and magnitude. It is often depicted as a directed line segment with an initial and terminal point. Vectors are useful for representing physical quantities like movement, and are important in physics for modeling directional and quantitative relationships. Vector addition and subtraction use coordinate geometry, while vector multiplication scales the vector components by a real number factor. Vector concepts can model phenomena like wind effects on aircraft velocity by combining wind and airspeed vectors.