By Jennifer Smith

A graphic can be an image, a drawing, or a vector object. You can create graphics manually by making marks on a page or create them electronically using software. You can display graphics in many formats, such as on a computer screen, projected on a wall, or printed in a magazine or book.

Computer graphics come in many forms, grouped by the way they’re created electronically. Bitmap and vector graphics are formed in different ways to achieve the results you use in your documents.

Work with bitmap images in Adobe CC

Bitmap images are pictures made up of many tiny squares, or bits, on an invisible grid. When these dots are next to each other, the picture is formed, depending on where and how the colors are arranged on the grid. If you zoom in far enough, you can even see the blocky dots, or pixels, that make up the image.

At 400 percent zoom, notice how the image in this figure is made of large squares. However, when you look at most bitmap images at their true sizes, you don’t even see pixels.

Bitmap image of a girl wearing a baseball cap.

The bitmap is a useful way to display photographs and apply effects to text. When you paint or create detailed graphics, you frequently use bitmaps.

However, remember that images can lose quality if you scale them (change their sizes). Resizing pixels causes the image to lose definition and quality. Most problems occur when an image is enlarged. Common kinds of bitmap files are PNG, BMP, GIF, JPEG, PICT, and TIFF. Fortunately, Photoshop CC includes improved upscaling capabilities that help you retain the quality you need for a good image.

Discovering vector graphics

A vector image (or graphic or drawing) is quite different from a bitmap image. A vector image is created by a series of mathematical calculations or code that describes how the image should be formed. These calculations tell the computer how the lines should display and render on the page. Some of the file formats that support vector graphics include .eps, .ai, .pdf, .psd, and .svg.

Vector images are usually smaller files than bitmap graphics because the mathematical information required to make the calculations to create the vector image is usually smaller in file size than the information that it takes to make up each pixel of a bitmap. (Compression can lessen a bitmap’s file size, but it’s usually larger and slower to display.)

For this reason and because vectors are helpful in scaling an image, as shown in this figure, these graphics are well suited for the web.

Drawing of a green fish.

Scaling is easy to do when you’re using vectors because the program needs to modify the calculations only slightly to make the image larger or smaller. This means the file size won’t change, and the scaling is very quick.

You can scale the image on a web page to fill the browser window, whatever size it is, or make the image huge for a large banner. The quality doesn’t degrade, and the file size remains the same.

If you want to use vector graphics in your websites and applications, you can choose File→Save. In the Save As dialog box, you can name your graphic and choose SVG from the Save as Type drop-down menu.