Assembly - Are those imports valid functions?

Question

When disassembling Portable Executables I realize that the import section often contains names like __imp_GetPixel instead of GetPixel directly (GetPixel is just an example here). Is there a reason why? Are they still referring to the same function? Is the extrn keyword in idata always referring to functions or can it also refer to constants?

Example file:

Now, in the picture above it is pretty straight forward that those imports are functions. But sometimes it is not that clear(that is why I asked if only functions get imported):

Answer 1

A PE image can import functions and data.