well you can probably find the info by googling "vector bitmap"
i think this is what your teacher means:
bitmap means that an image is built up by colored pixels.
this means, the higher the resolution of the image, the
more accurate the image is.
vector means that an image is built up by points with
coördinates and features like line thickness. this makes
an image more accurate even after zooming in hundreds of
times.
following link can probably give you the info you need.
i found some more info, but it's in dutch lol.
http://www.eastbywest.com/pub/vectorbitmap/
