What is a Vector?
It is an image that makes scaling easier as it uses mathematical values to define shapes and colors. These are called Vector Images or Vector Graphics. You don’t have to keep tabs on thousands or millions of pixels (square-shaped dots) in a bitmap, as vector images do that for you. They keep track of all the points and equations that represent the lines that join them.
The best part about vector images is that they can be resized. You can resize a vector image infinitely larger or smaller and they will not get blurred and still be clear. The file size will also not increase or decrease if a vector image size is increased or decreased. This is because vector images are dependent on algorithms instead of pixels. Line art is what produces vector images as they are scalable to infinity. 
Additional information
Vector images are used in a majority of the computer’s font files of the letters. This is why when you increase or decrease the font size of a word file, you are still able to read the alphabet clearly. Microsoft Office clipart also uses vector art and most of the graphs and other statistical representation on Microsoft Office is also produced with the help of vectors.
You will find vector art being used to create images or texts around you all the time and you might not even realize it. You can use applications like Adobe Illustrator or QuarkXPress that specialize in illustrations to create vector art.
Vectors are utilized to create almost all logos, illustrations, animations, and texts as they will produce the most vibrant colored images or texts and when printed will be of the highest quality. You can get your vector image increased in size to fit a massive billboard or decreased in size to fit your business card.
