What is the real-time display shooting function of digital SLR camera?

The real-time display and shooting function of digital SLR camera is to use the display screen behind the fuselage for instant framing and composition, so that what you see is what you get.

SLR cameras used to rely on reflectors, pentagonal mirrors and so on. Used for optical framing. On the basis of optical framing, digital SLR adds instant framing function (LV mode) by using the camera back screen to make photography more intuitive. This is one of the biggest differences between digital SLR and film SLR.