In the public sector, procurement is primarily affiliated with government organisations, be it on a local or national level. In contrast, private procurement evidently happens for organisations that are profitable and privately owned.
It depends on the country constitution. In some countries procurement is provided for in the constitution. In summary public procurement is centrally regulated by the ministry of finance and private procurement is determined by each business..
Public or government procurements are subject to laws and processes oftentimes resulting to the delay of purchases and project completions. Private procurement are faster since they have less paperworks and processes resulting to a faster completion of projects.