Resolution refers to the number of pixels per inch in an image, with more pixels allowing for more detail. Screen displays standardly use 72 pixels per inch (PPI) while prints use 300 PPI. The number of pixels determines image quality, as more pixels provide more image information. A bitmap image's resolution is determined by its size in pixels and pixels per inch.

1. Resolution
Resolution is the number of pixels per inch of an image, the more pixels in the image the more detail
can be displayed within the image, the fewer pixels while decrease the detail of the image. There are
two ways to display an image; print and on screen. The standard for screen display is 72 PPI and the
standard for print is 300 PPI.
The more pixels per inch, the greater the resolution and generally an image with a higher resolution
produce’s better image quality. The reason why the quality goes up with the number of pixels is
because there is more information in the small space.
Bitmap images are composed of pixels, there is two factors of a bitmap image; the size and the
resolution, these two factors alone determine the total number of pixels in an image.

2. Pixel
A pixel is a physical point within a Rasta image; it is the smallest controllable element of a picture
represented on screen. Pixels are manufactured in a two-dimensional grid, and are often represented
using dots or squares. The address of a pixel corresponds its physical coordinates.
Pixel is shortened for Picture Element, pixels basically make up an image, and there can be
thousands or millions of pixels within a single image. Each pixel has its own individual colour, but
because they are so small pixels often blend together to form shades of an image.
Raster
Raster images are a structure of pixels, a bitmap is a dot matrix which is represented on a
rectangular grid of pixels. The format of a raster image corresponds to the number of pixels within
the image; a bitmap is characterized by the width and height of the image in pixels and the number
of bits per pixels. When enlarged individual pixels appear as squares and are constructed by adding
the values for red, blue and green.
Vector
In vector graphics geometrical shapes are used and they are based on mathematical expressions
(points, lines and curves) which represent images. Vector leads to the control points and they have a
definite position on the x and y axes, the location of the point requires direction and each vector has
a certain shape, colour or thickness and it doesn’t affect the size of files.