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vectorial: *
In classical Euclidean geometry they were introduced in the 19th century as equivalence classes, as ordered pairs of points; 2 pairs (A, B) & (C, D) were equal in power if the points A, B, D, C, in this order, form a parallelogram. Such an equivalence class is called a vector, or a Euclidean vector. Such a vector is endowed with a magnitude (the length of the line segment A, B) and a direction (the direction from A to B). In physics they represent physical quantities having both magnitude & direction, but not located at a specific place, in contrast to scalars, which have no direction. Velocity, forces & acceleration are represented by vectors.
the arrow (left) is the symbol of a vector
Vectors have both magnitude and direction
The length of the line shows its magnitude & the arrowhead points in the direction. We can add 2 vectors by joining them head-to-tail (left)