There are many kinds of display (LED, LCD, PDP...).
Which type is used in the in-flight entertainment system on commercial aircraft?
And which kind of display is used in the electronic flight instrument system?
Traditionally, it was almost only movie projectors in the cabin, since Cathode Ray Tubes (CRT) were too bulky and impractical to fit. It was also very expensive. I think only with the arrival of LCD displays seatback displays that we know now were made possible.
As for cockpit displays, the CRTs were widely used until LCDs were introduced and offered better performance.
You can compare the 737 Classic with retrofitted CRT displays with those of the 737 Next Generation.
Compare the 747-400 to the 747-8 which had LCD in place of CRT.
I can't find pictures, but have been told that the old CRT modules were huge, very deep (which you can't see) and heavy, compare to the thin panel that now is available.
You can still backwards order CRT for aircraft. I was flying with one airline that had done on a very new A320 to maintain commonality with the rest of the fleet. The pilots didn't appreciate it though, since it was bad for the eyes, needed to be dimmed and had (I believe) inferior resolution.
Page 9 of this document gives some details on the display type tradeoff.