PLAYBLAST
Playblasting performs a screen grab of the animation in the active view and produces a movie file in AVI or Quicktime format. It gives you a quick preview of animation without any rendering effects.
Playblast is done to preview render result without needing the time required for a formal render.
Pro : Process is quick and a preview of scene is produced within few minutes.
Can check and tweak animation immediately.
Con : Cannot fathom how the final output could look as lighting and camera placements cannot be seen.
Cannot be used for audience viewing.
RENDER
Rendering is the process in which you tweak lights, textures, and cameras, adjust various scenes and object settings, visualize your changes and when you are satisfied with the results, render the final output.
This is done at the end, as a final output, as the time this process consumes is too long.
Pro : Final output comes with polished editing, where lighting and staging is perfect.
Con : Rendering takes too long. For example, the render rate of the famous Disney film – Frozen was 30hrs/frame.
In case of any changes in 1 frame, the long process of render should be done again.
Shraddha Mithinti 