If you're not familiar with standard Photoshop file formats, it may sound like a foreign language. Fortunately, there are only a few options that are used regularly in printing. Understanding the differences and when to use each particular file format will ensure that you have the best possible outcome with your printed projects. The three key file formats that you should be aware are PNG, JPEG, and RAW formats.
The big value that PNG brings to the virtual table is the ability to display graphics on a transparent background. This is especially important if you're creating a logo or artwork with multiple layers -- or stacks -- of graphics. While this is a nice-to-have feature when you're combining files together or overlapping images, the file size does tend to be larger than with other standard formats. Some browsers also interpret PNGs differently than others, making it important to preview your work on various platforms when using PNGs on a website.
If you're a Windows user, you may be more familiar with seeing this file typewritten as JPG, although they both represent the same file type. JPEG files are known as an all-around workhorse because the file types are relatively small and the quality can be quite high. Many of the images that you'll see on websites are JPEG files as the smaller file size allows a website to load more quickly. The key difference between PNG and JPEG is the inability of a JPEG to offer a transparent background. In the absence of color in the background of an image, JPEG will default to appear white.
Technically, RAW isn't a format at all, but rather a description of files without additional processing applied. These files may come from camera manufacturers such as Nokia or Canon, but the key identifier for RAW files is their sheer size. It is not unusual for a RAW file to be ten times the file size as a JPEG or PNG format. These files are meant to capture the depth and dimension of photography in their full glory, while JPEG and PNG are more likely to be an approximation of the original file with far fewer details.
It can be difficult for the naked eye to tell the difference between these types of images. However, if you're looking at each of them at 100 percent magnification on a screen, like a graphic designer will to make adjustments, you'll understand why it's important to know what type of file you are dealing with.