Logos

JPEG or .jpg

(Joint Photographic Experts Group)

JPEG is a very popular and useful format for raster images on the Internet. JPEG's platform independent, supports both RGB and CMYK color modes, and uses compression to minimize file sizes. In some cases, it may be used for images intended for print. However, this must be done carefully since JPEG's compression is lossy, meaning it physically alters the image permanently by discarding information. JPEG's work best on print media about the size of a brochure. 

PNG or .png 

(Portable Network Graphic)

This is the background-free image you've been looking for! A PNG (pronounced "ping") is a raster image file that is a lossless compression and gives a trade-off balance between file size and image quality. PNG files are very compressed and often work well on websites. The best part of these files is that they can retain degrees of transparency (hence being known as images without backgrounds). 

PDF or .pdf 

(Portable Document Format)

A PDF is a hybrid image that can contain both raster and vector information. It is an Adobe product and requires Adobe's tools to view and edit. To edit a PDF, the user must have the Adobe operating systems (but there's a free version for viewing PDF's). Some print shops use this as a preferred standard, but it is not a recommended format when you need someone to be able to edit your file.

EPS or .eps

(Encapsulated Postscript)

Available on request - EPS files are also referred to as Vector Graphics and Illustrator files. This is not an image -- it is text file. Think of it as a formula to make a graphic, a large mathematical equation on how to draw a picture. The best part of a vector graphic is that it gives you the ability to print a graphic at any size without regard to dots per square inch (dpi). Logos are often in EPS format.