I'm reading section 5.2 of pbrt 3rd edition and came across the part where they explain the concept of RGB colors.
When we display an RGB color on a display, the spectrum that is actually displayed is basically determined by the weighted sum of three spectral response curves, one for each of red, green, and blue, as emitted by the display’s phosphors, LED or LCD elements, or plasma cells.
Then there's also this part.
So my understanding so far is this.
Just like a SPD can be expressed from the weighted sum of spectral matching curves $X(\lambda), Y(\lambda), Z(\lambda)$ as in $S(\lambda) = x_{\lambda}X(\lambda) + y_{\lambda}Y(\lambda) + z_{\lambda}Z(\lambda)$, it can also be expressed with the weighted sum of spectral response curves: $S(\lambda) = rR(\lambda) + gG(\lambda) + bB(\lambda)$
Is my understanding correct? If it's so, the point I don't get is why the book is using all sorts of mixed, confusing terms like "spectral matching curves", "spectral power distribution", and "spectral response curves". I would really appreciate if someone could clear my confusion. Thanks in advance.