They're both processor intensive tasks which need to be done in real
time. Lots of memory is needed, as is lost of processor power.
Luckily however, video NLE s/w typically caches unchanged scenes/sections
for realtime full-speed/scale playback previews until it's changed again.
(Not to minimize the PITA it is having to wait while the PC does a slower
re-render for preview when edits are made.)
Many NLE packages support proxy editing as well, which let's you work
with a smaller video size/less CPU intensive codec while editing, but
will render with the original HQ/HD video as the source.
Again, not to minimize the fact that of course, more hardware equals
better performance, I just wanted to mention how the s/w deals with that.
Many people think you need an 8-core / 12 Gig RAM machine with expensive
NLE s/w to do any video editing effectively, but that is not the case.
(Obviously if you're editing for broadcast TV, or some high-level end-
product like that, you'd also have matching hardware, so I'm more
speaking of home users, or even videographers of whatever type.)
You'd be surprised what can be done with a $200 full HD camcorder and a
$50 s/w package, on a $300 commodity PC........
.......and of course, you need some talent and 'an eye', and have some
vision, etc, and need to put in some work learning at least the basics of
using the tools, the s/w "ain't gonna do it all for ya".
My only point is that if you think video production is something you'd
(and not 'you' to who I am replying) like to explore, don't be scared off
by the "seemingly" costly hardware requirements. Yes, a lesser PC will be
slower than some esoteric specially built rig, but just getting started
to even see if you like doing this, just for fun or in some professional
manner, doesn't cost large amounts of money.
(There's even one or two quite capable Linux-based NLE s/w packages that
are no-cost I use at times.)
