cdr to png conversion from CorelDRAW's CDR format (.cdr) to PNG graphics (Portable Networks Graphics) basically represents a vector to bitmap conversion. This means the resulting file will not contain any scalable vector data and will be just raster images.
You can of course make this cdr to png conversion happen in CorelDRAW via object export function, but if you do not have access to this software you have to rely to some of the 3rd party software to do this graphics conversion. Some alternative tools are listed below, but overall the support for latest versions of CDR format is somewhat limited.