The commercial printing industry depends highly on vector art. It gives a clear and crisp image at any magnification, hence, is used in the creation of logos and graphics to produce quality promotional products. Buzzle tells you what a vector file is along with a list of its formats and extensions. Most of us are aware of raster images. Colored pixels or blocks come together to form an image called raster image. You might be acquainted with .JPEGs, GIFs, PNGs, which are raster file formats. To know what are vector files (or images), it is important to understand the difference between these two file types. Since raster images are a formation of pixels, when magnified, these images become grainy, thereby, reducing the visibility of the image details. Alternatively, vector images, even if stretched, will give you a perfectly detailed image. This is because, a vector file is not composed of pixels but mathematical formulas! These formulas would define the area of the plot (line, curves,etc.) you draw, hence, making the vector graphics more flexible. This is why, vector is used in the creation of effective company logos and brand graphics. Vector file defines a graphic image made by using mathematical equations and algorithms to specify its points and shapes, allowing it to be scaled or modified with no loss of data or resolution. When your artwork is in vector (i.e., .ai or .eps), the size of the graphic can be increased or decreased, which results in recalculating the mathematical equation, thereby, producing an image without compromising on its quality or detailing. This image is known as vector image which is also referred to as 'draw graphics'. These vector images have many scalable objects like lines, curves, shapes to be colored, filled or outlined, that are defined by mathematical equations and not pixels. We can change the attributes of the object without affecting or destroying the basic object. Fonts are a type of vector object. Vector-based images are resolution independent. No matter how much you blow them up, you'll still find the lines and edges crisp! A vector image that has a bitmap pattern applied to an object (as a fill, for instance) is a metafile, where the object is still a vector, while the fill attribute consists of bitmap data. The common metafile formats include―EPS (Encapsulated PostScript), PDF (Portable Document Format), PICT (Macintosh). It is important to understand that just by saving your file with .ai or .eps extension will not make it a vector file! Nor can a raster image be scanned and saved as a vector image. It has to be composed in a program like Adobe Illustrator from scratch. You can apply bitmap textures to vector objects if you wish to give your image a photorealistic appearance. Thus, the conversion of vector to raster is easy, however, the converse doesn't hold true. Source.