An AET file is typically understood as a reusable AE template, designed so you can open it repeatedly and save new versions rather than overwrite the source, with the file storing everything that defines the motion graphic: comps, timeline structure, layer stacks, animation keyframes, effect setups, expressions, cameras/lights, render settings, plus organizational items like folders and interpretation settings.

What it usually does not store is the raw media itself; instead it keeps references or paths to external footage, images, and audio, which is why templates are often delivered as a ZIP with an assets/Footage folder and why you’ll see missing-file prompts if items were left out or not synced, and because AETs may rely on specific fonts or third-party plugins, opening one on another machine can trigger substitutions until everything is installed or relinked, with the final reminder that although AET typically means an After Effects template, file extensions aren’t exclusive, so checking “Opens with” in file properties or recalling where the file came from is the safest way to confirm what program created it and what extra files it should include.

An AEP file serves as the main editable project file in After Effects, updated as you import footage, adjust comps, and refine effects, while an AET is a template meant as a reusable starting point, so the practical difference is workflow: you reopen an AEP to keep editing the same project, but you open an AET to spawn a new project so the template stays untouched.

If you have any concerns pertaining to where and how you can use AET file description, you could call us at the page. That’s why AET templates are so common for ready-made motion graphics such as intros, lower-thirds, and slideshows: the creator treats the AET as the permanent master, and you open it only to Save As a new AEP before customizing elements like text, color, media, and logos, and while both formats store the same structures—compositions, layers, keyframes, effects, expressions, cameras/lights, and settings—and both typically link to external footage, the AET exists to preserve the original design whereas the AEP is your editable working file.

An AET file holds onto the structure and animation logic of an After Effects project but not always the media assets, containing compositions with defined resolution, FPS, duration, and nesting, plus the complete layer arrangement—text, shapes, solids, adjustments, precomps, and placeholders—with layer properties like position, scale, rotation, opacity, masks, mattes, blending modes, parenting, and the project’s animation data including keyframes, easing, markers, and any expressions used to automate motion.

It further keeps all applied effects with their settings—ranging from color correction and blur to glows, distortions, and transitions—along with any 3D environment of cameras, lights, and 3D layer attributes, plus render controls and project organization like folders, label colors, and interpretation rules, but it generally doesn’t contain the actual footage, audio, fonts, or plugins, instead relying on paths that may trigger missing-asset or missing-plugin prompts when opened on a different computer.