The most common way to think of a vector in is to consider it
to be an object with a magnitude and a direction. A scalar only has magnitude,
or length. It only knows how big it is. A vector also has direction, so it
knows how big it is and where it is going in life. (There are objects called
tensors which also know their starting point, but they are a topic for a
different course.) For the ease of drawing the illustrations, we'll stick to
vectors in two or three dimensions, ie. 
and 
,
where vectors look just like directed line segments (lines with an arrow
to indicate a direction.)