What is the yield on cost in CRE?

Excuse me, could you elaborate on the concept of "yield on cost" in the context of commercial real estate (CRE)? As a layperson in the field, I'm not entirely familiar with this term and how it specifically applies to CRE investments. I understand it relates to measuring returns, but how is it calculated and what insights does it provide investors in assessing the performance of their portfolios? I'd appreciate any insights you could offer to help me better comprehend this critical aspect of CRE finance.