Animation is one big universe and VFX is another big universe!

Visual effects (sometimes abbreviated VFX)

 is a bit of a generic term that basically involves

everything else (and includes animation)

Have you seen the ad of MS Dhoni clicking a picture of a bag in a mall?

Well, neither the mall, or actors or the bag was shot in that single frame,

they were all shot on different location probably and

VFX compiled them together in one frame.

The actors were shot in chroma and later keyed out in VFX

and added a layer of bag and mall on either sides.

This is achieved by digital artists and animators as well as

technical artists, technical directors and

digital compositors (as in image compositing, not music composition)

This entire process from raw shoot to final output is done with the help of VFX

If you want to show one building is blowing up,

you need one bomb blast element,

one footage where debris flying outwards and

footage of few other flames to add to the building and

when we apply them together by adjusting time and location,

the final output looks so much better

Another example of VFX would be the dragons flying through the sky

in Game of Thrones, or a spaceship flying through space in Star Wars

VFX is the integration between actual footage

and this manipulated imagery to create realistic

looking environments for the context.