I was about to calculate the area of some polygons and before I did I did some research. I found that the area of the polygon will be represented in the units of the projection used. So I did some digging to find that the projection I need is BC Albers, but when I went into the list of projections in QGIS, I found that there were two that could the correct ones. The first is EPSG:3005 NAD83 BC ALBERS, and the second one is EPSG:3153 NAD83(CSRS)/BC ALBERS
I have projected the polygon as both and saw no difference in the result. I was looking on http://prj2epsg.org/epsg/3005 and it says:
"This CRS name may sometimes be used as an alias for NAD83(CSRS) / BC Albers. See CRS code 3153"
Just wondering if anyone knows why there are two seemingly identical projections and if there is any difference. Also what does CSRS stand for?