Digital photographs are bitmap images made up of thousands and thousands of pixels while vector graphics, even if based on a photo, are drawn with lots of lines (& math) in an illustration program such as CorelDRAW or Adobe Illustrator. Often, you can tell the difference by sight because vectors tend to be slightly artificial, just a touch too perfect to be pixels.
But sometimes it's hard to tell. Take a look at these people pictures drawn in CorelDRAW posted at Designbeep. On a few of them, at first glance you might mistake it for a photograph.That's some serious vector work.
The Language of Curves - from About.com Graphics Software, you'll find explanations for paths, nodes, handles, splines, and Bezier curves including detailed illustrations which can be really helpful if you've never worked with vector paths and curves.The Anatomy of a Vector Illustration - at Mike's Sketchpad a vector illustration of a bird is dissected to show the objects, curves, and points. The article includes tables comparing certain vector elements from CorelDRAW, ?Illustrator, FreeHand, and Canvas.Vector Drawing Tutorials - learn how to use CorelDRAW, Illustrator, and other vector drawing programs.In addition to being the right tool for vector drawing and logo design, illustration programs can often double as page layout programs for projects that don't involve tons of text and lots of pages (that is, not for books and newsletters usually). You can design your ads, business cards, posters, and simple brochures in an illustration program.
If you don't have the time, patience, or skill to draw your own you can get some free vectors to use in your projects. Here's a random sampling of the many vector art sites out there to get you started.
Vectorious.net sells vector art but they also have freebie vectors in their Vector art blog where you'll also find tutorials, tips, and collections of inspiring vector illustrations.FreeVectors.net showcases free downloads of vector art from a variety of authors for personal use and some are also licensed for commercial use or have creative commons licensing.Vecteezy has free vector illustrations, icons, and patterns from many authors. Some will be personal use only but others have more liberal licensing.What software do you use for vector artwork? Do you use illustration software for page layout projects too? Share with us in the comments.