Difference between SharePoint Designer , SharePoint Foundation and Server

1.    SharePoint Foundation (formerly Windows SharePoint Services) is free

2.    SharePoint Server Organizations can deploy and manage SharePoint Server on-premises. It includes all the features of SharePoint Foundation.

3.    SharePoint Designer 2013 use to build powerful, workflow-enabled solutions. And use to edit external content type for an external data solution based on Business Connectivity Service.

4.    SharePoint Online A cloud-based service, hosted by Microsoft, for businesses of all sizes. Instead of installing and deploying SharePoint Server on-premises, anybusiness can subscribe to an Office 365 plan or to the standalone SharePoint Online service