Compare database-engine editions and licensing models separately. The finder includes SQL Server Standard server-plus-CAL listings, core packs and Enterprise core listings. A Windows Server license does not supply a SQL Server license.
Before choosing: ask the application vendor which SQL edition and version it supports. Record core quantities, virtualization arrangements and direct or indirect access before choosing per-core or server-plus-CAL coverage.
Start with the database features your application needs. Standard can suit many business applications; Enterprise is for requirements that need its additional scale or features. Separately choose a Server + CAL or per-core model that covers your actual users, hardware and virtualization rights.