2) What is the difference between VECTOR and BITMAP graphics? Explain both terms.

Bitmap graphics are composed of pixels, which contain specific color information. A pixel is very small, a single image may be composed of hundreds of thousands of individual pixels. Much like cells revealed from a piece of tissue when seen under a microscope, these pixels are only clearly and individually visible when the image is magnified

Rather than being composed of pixels, Vector graphics consist of points, lines, and curves which, when combined, can form complex objects. These objects can be filled with solid colors, gradients, and even patterns.

Vector graphics are mathematical creations. For this reason, the programs that are used to create them save instructions on how the image should be drawn, rather than how it looks. This is the key difference between the two types of graphics.

1) What is a pixel?

A pixel which is short for 'picture element' is a single point in a graphic image. Each information element is an abstrct sample and not really a dot or a square. With care and accuracy pixels in an image can be reproduced at any size without the appearance of visible dots or squares however they are occasionally reproduced as dots or squares and can stand out when not fine enough.
http://en.wikipedia.org/wiki/Pixel