There are three common file types we'll be using in these lessons. JPEG, PSD, and PNG. Let's take a look at JPEGs. First, a JPEG is a compressed file. It is always rectangular and never contains any transparency, nor can it have more than one layer. If you look at the Layers panel, you'll only see one layer. Many of the photos we take are JPEGs, but not all. If you use a setting on your camera that doesn't compress the photos, you'll end up with camera raw images that have a proprietary ending depending on the camera you use. Sony uses .arw. Canon uses .crw. Nikon uses .nef, and there are other brands with other Camera Raw endings as well.

Digital textures and papers also tend to be in JPEG format. Notice this paper is rectangular with no transparency, and it has only one layer in the Layers panel. JPEGs are great for producing good quality and a smaller file size. The photo on the left is only 719 kilobytes, but the Camera Raw photo is 24.9 megabytes. A huge difference in file size. Many photographers use only Camera Raw. But JPEGs can also be great photos, as most of us can attest by the number of cell phone images that turned out quite nice.

There are pros and cons to both formats. A JPEG, for example, gets compressed every time you save it. If you save it enough times it will eventually suffer noticeable loss of quality. We'll revisit this topic when it comes time to save our own projects. The biggest con for Camera Raw is its large size and the fact that it must be first opened in a Camera Raw editing window, which, by the way, does come with Photoshop Elements. And once you do that it can be imported into Photoshop Elements. Since this is a class for beginners though, we won't be using camera raw images.

The next common file type we'll be using in these lessons is .PSD which stands for Photoshop Document. It has three great characteristics: it is not compressed, nor does it compress the document when you save it, so it doesn't lose quality each time you save. It supports transparency. It can have multiple layers, making it a great file format for creating posters, newsletters, scrapbook pages, or any kind of document where you composite more than one item, such as a photo and artistic element and type into one document, which is a case with this thank you card.

Here you see the individual files I used to create the card. When these are opened in Photoshop Elements and combined into one document, you can see that each one of those items is on a separate layer in the Layers panel. Some of the layers have transparency around them, which is indicated by a gray and white checkerboard pattern on the thumbnail. And by the way, compositing images like this is one of the things we'll learn how to do in this class. So PSD is a great format for creating multi layered documents in Photoshop Elements.

One side note is that the TIFF file format has all the same great characteristics as a PSD file with one added advantage. Many brands of image editing software can open TIFFs, whereas a PSD must be open with Adobe products. But since Photoshop Elements is an Adobe product, I'll be using the PSD format in these lessons.

The third file format commonly used is .PNG, often pronounced Ping. It doesn't compress the file. It does support transparency, but it does not support layers. Notice this only has one layer in the Layers panel, but it does support transparency around irregularly shaped objects like this element. Here's a close up of what the transparency looks like. Being able to support transparency on a single layer makes it perfect for artistic elements that aren't rectangular.

So to review, in these lessons we'll be using three common file formats: JPEG, PSD and PNG.