Vafi88 From United States of America, joined Apr 2001, 3116 posts, RR: 22 Reply 1, posted (8 years 1 month 3 weeks 6 days 16 hours ago) and read 2531 times:
They're basically the same thing, it's big patches of same colored pixels.
Ckw From UK - England, joined Aug 2010, 324 posts, RR: 19 Reply 2, posted (8 years 1 month 3 weeks 6 days 12 hours ago) and read 2496 times:
Not quite - though they look similar. Grain is a property of the film - think of it as the structure of the negative/slide. When you scan film, as well as the image you capture the grain as well - its a like a texture and will tend to appear as a darkish grey (or at least a darker tone of the dye colour).
Noise, though it looks similar is caused by electrical interference is the digital camera or scanner (so on scanned film you could have both grain & noise). Noise is a scattering of randomly coloured pixels, and is divided into two types - luminance (variations in pixel brightness) and colour noise (variation in pixel colour).
There are various noise reduction packages on the market (eg. neat image) as well as techniques you can use in PS - I describe one for removing colour noise in an earlier thread.