Output
If you’re rendering an animation, another important thing you must do is set up the output folder and format so as a frame is rendered, Blender automatically saves it. With a single image, you don’t need to set up an output path and format because after it’s rendered, you can save it manually from the UV/Image Editor (F3).
In the Output panel of the Render tab, in the Properties Editor, you can select the output folder to which the renders will be saved and the format of the exported images.
Tip
You can save the animation as a video, but that is only recommended for quick render tests. If you expect the render to take a few hours (or even days!), it’s usually better to export the animation in an image sequence. Instead of a video, what you’ll get is a series of .jpeg, .png, or .tga images—one for each frame of the animation.
This has several benefits: If the render fails at some point, you won’t lose the rendered frames; while in a video, the whole video would be corrupted. Also, the videos are usually highly compressed, so with images you’ll get no compression artifacts and then you can convert the image sequence to a video (you can even do it in Blender by loading it into the Video Sequencer, or as a clip in the compositor and rendering it in a video format). This is very fast because it’s much easier and quicker to render images than an entire 3D scene. This way, you’ll have the full quality and you can compress the image sequence into a video later.
Also, remember that it is possible to export different passes as an image sequence (OpenEXR Multilayer format is great for this because you can export different sequences for each pass) and composite the render elements in other software such as Photoshop or After Effects for greater control.