Mask in Ps

[MahaB82A]

Mask meaning in Cambridge dictionary is FACE COVER. But in Ps mask means everything is hiden outside the masking region. Why is that difference? I know the meaning in Ae.

[jane-e · Accepted solution]

@MahaB82A 

See the more thorough definitions of "mask" in the Merriam Webster dictionary:

https://www.merriam-webster.com/dictionary/mask

"something that conceals from view"

Jane

[MahaB82A]

Thanks.

[jane-e]

You're welcome Maha!

Jane

[John Waller]

Some reading on the fundamentals of masks in PS

https://proedu.com/blogs/photoshop-skills/what-is-a-layer-mask-in-photoshop

[Trevor.Dennis]

You could still apply your definition, but you'd be masking the background, unless you invert the mask, in which case you are masking the foreground, but that would be pointless because this is Photoshop, after all, so if you want to mask a foreground element you'd simply remove it.

The bottom line here is being a pedent in Photoshop is rather like pixel peeping.  It will send you mad for no good reason.

[Stephen Marsh]

There are both Reveal All (fully white) and Hide All (fully black) default layer masks.

Also keep in mind that terms are often based on traditional analogue processes from photographic or graphic arts industries, rather than general dictionary definitions.

Ever wonder why the Quick Mask mode overlay for protected/masked areas is red?

https://en.m.wikipedia.org/wiki/Rubylith

[Trevor.Dennis]

I'm old enough to remember spotting medium and large format B&W negatives with red dye.  Is that kind of relevant? 

[Stephen Marsh]

I'm old enough to remember spotting medium and large format B&W negatives with red dye.  Is that kind of relevant? 

By @Trevor.Dennis

Haha, not an old school professional photographer, but it was the same in graphic arts for negatives with opaque paint or those special red texter pens which I haven't thought of in years, that red tape from 3M, Rubylith, Goldebrod paper etc.