This is the "model" of Volvo you have.
Usually, there is a badge on the back of your car that tells you what model family it is.
If your car only says "DL" or "GL" then you probably have a 240 or 740 and need to figure out which one of those "boxy" models you have.
If you don't know what model you have, try looking at this link for pictures and years the different models were offered.