I have 8 raster images of a farm that are changing with respect to time. I want to create one map as shown in the attached image which will show the 8 raster images with only one legend to represent raster pixel values across all 8 rasters.
As @JoshC mentioned in the comments, the same color ramp with min and max values has to be set for all the layers.
Make a note of the minimum value across all the rasters and do the same for the maximum. Then, go to the Layer Styling of each layer and set the minimum and maximum to the values you noted.