File Types
It's important to keep track of your file types when working with media. There are many different types of files for the many programs you use and it gets confusing. This page is mean to help you understand it all and is meant to be a page you can come back to when you forget or need to know about a file type in a new program.
Filetypes can be determined by a three letter extension at the end of the name. Sometimes these extensions are hidden, but you should always change your preferences and views so you can see these extensions. They are important.
Photoshop
In photoshop, there are two main filetypes we will use and a couple we may use from time to time.
.PSD This stands for PhotoShop Document. This file contains all the Photoshop layers, masks, etc. that you have worked with when creating something with Photoshop. You can pick up where you left off and keep working on this file. It's important that you always save your work as a .psd file. PSD files are big and uncompressed
.JPG This is short for jpeg, which stands for Joint Photographic Experts Group. jpegs are compressed images with no layers (flattened) and no transparency. A jpeg is good for the web because of its small size but the compression means you have lost some of the detail in the image.
.GIF stands for Graphic Interchange Format. GIFs are lossless, meaning you do not lose any details in the compression but they are not as small as jpegs. GIFs also have a very limited color range, so you should never use them for photos. They work very well for graphics though.
RAW images are made of uncompressed data straight from the imaging chip on the camera. Cameras usually take this RAW data and compress it as well as apply adjustments, contrast, and sharpening to make the image look good for amateurs. If you care about your photos and are able, you should always shoot in RAW, then bring your photos into Photoshop or another program in RAW, then adjust the photo yourself to get the look you want. You can then output to jpeg to post or print your photo.
Here are some links discussing the different filetypes:
Petapixel: 5 Common file Types in Photography and when you should use each one.