This one is pretty straightforward. An AI file is an Adobe Illustrator file. That means that it’s a vector document, and even though it may contain raster-based imagery, it still makes shapes using geometry, as opposed to pixels. That said, it’s not just a regular old vector file like an EPS. Illustrator documents have layers and multiple artboards, so they can contain vastly more information. For more info, check out this article.
Like an AI file is for Adobe Illustrator, a PSD file is for Adobe Photoshop. It’s a raster-based file, so it uses pixels in various shades to create an image. What makes a PSD file different from a regular JPEG is that it can contain all sorts of layers inside the doc, and each layer can have its own modifications. A JPEG is a flattened version of that PSD doc (or one of the layers inside the doc), so it can’t be broken apart into different layers and reverse engineered.
INDD stands for another Adobe product: Adobe InDesign. It’s the tool of choice for print designers, or designers that want to create print-like creations for the web via PDFs. I use InDesign all the time to create magazines for my clients. Like other Adobe products, an INDD doc can have multiple pages, styles, and patterns in one place, and can be broken down into those individual components.
PDF stands for Portable Document Format, and it’s one of the older file formats on this list. It was developed originally by Adobe as a platform- and software-agnostic tool for fixed-layout flat documents. The idea is this: if you get a PDF document, it should look just like the printed version of the same doc, including all of the graphics, colors, fonts, text, and so on.
Now where things get interesting is with the addition of fillable PDFs. These docs have fields that a user can fill in for their own uses. For example, you can download U.S. tax forms for free at IRS.gov for when you do your taxes. Then you fill out the fields with your information, save it, and/or print it out. You can also create your own fillable PDFs, and one of the many tools to do that is Adobe Acrobat. It comes standard with Adobe Creative Cloud, and requires a subscription.
EPS stands for Encapsulated PostScript, and all that fancy language means that an .eps doc typically has vector graphics. The file format can also have bitmap images and text, but 9 times out of 10, if you ask for a vector document, you’ll get an EPS. For more vector info, check out one of my favorite articles.
Of course, EPS and AI aren’t the only vector games in town. SVG stands for Scalable Vector Graphics, so SVG files are also vector-based. But where it gets fancy is the relatively recent introduction of SVG fonts. They’re designed to use on the web, and it allows web designers to build a font into their pages, and scale it dynamically based on the user’s browser.
JPG or JPEG
Alrighty, here’s a big one. A JPEG (.jpg or .jpeg file) is the image format of the web. It uses “lossy” compression, which you probably know if you’ve ever created one in Photoshop or a similar program. You know how you can adjust the image quality using a slider in Photoshop? This is how you dial in the compression, and therefore pick the best image quality. But have you ever seen an old meme? You know, the ones with all the blocks and messed up textures in them? That’s because the original JPEG was compressed, then someone compressed it again, and again, etc., to the point where the image has lost a substantial amount of quality. But hey, if it’s funny, do you really care anyway?
When I worked at a magazine, we didn’t use JPEGs or GIFs for our high-resolution prints, we used TIFFs. Why? Compression. I just talked about how JPEGs are compressed, and how that can result in artifacts or blockiness if it’s compressed too much. TIFFs aren’t compressed. Period. That means that they don’t degrade at all every time you open and edit them.
Now that’s not always the case. I have lots of magazines today that tell me to send them JPEGs, and forget the raw version of the file (which is what they would normally use to turn into a TIFF). And that’s often because TIFF files are huge. Since they’re not compressed at all, there are no file size savings to be had. That’s also why you don’t find them in use on the web.
All that said, a JPEG can give you a high-quality photo, no doubt. But the absolute best quality comes from a TIFF.
Whether you use Slack all the time with your pals or you just want to send a funny animated message to someone, chances are good you’re going to use a GIF. They’re animated bitmap images that you can use in a variety of places, and they’re usually pretty small in file size.
A Bitmap is another type of raster file, just like a JPEG and GIF. They’re mostly found on Windows operating systems, and nowadays aren’t as common as they used to be. That’s because even though there are a lot of cool things you can do with them — they work great with printers and CRTs, for example — they tend to be fairly big, too. They also don’t resize as well as a JPEG, so when you combine those two downsides, you’re in a sticky situation.
If you’re a font junkie, then you know all about our next two listings. First up is TTF, or TrueType Font. Back in the day, Adobe ran the font market with PostScript. But Microsoft and Apple wanted to get into the game (and stop paying Adobe licensing fees), so they created TrueType together. It’s your standard font format nowadays, and you can use a TTF on pretty much anything. As Wikipedia puts it, “The primary strength of TrueType was, originally, that it offered font developers a high degree of control over precisely how their fonts are displayed, right down to particular pixels, at various font sizes. With widely varying rendering technologies in use today, pixel-level control is no longer certain in a TrueType font.”
Is it the best font format? Well …
OTF, or OpenType Font is the next generation of TTF created by Microsoft with some help from Adobe. While TTF lets designers play with pixels, OTF is a scalable computer font. That means that once you design the font, you don’t have to mess with specifics; everything scales up or down appropriately automatically.
Want to add some cool brushes to your Photoshop toolbox? Then you’ll want some ABR files. It stands for Adobe Photoshop Brushes file, and each one has a collection of brushes that the Photoshop Brush tool will use. They’ve got all sorts of specific tweaks and customizations, and you can check out a whole bunch of samples right here.