Different API involves in directx are Direct 3D, Direct Draw, Direct Music, Direct Play and Direct Sound. Different API or drivers enable different feature in your PC and Directx enable all features in your PC. For latest API, DirectX 12 Download is required. Directx is basically collection of all drivers or API. Directx enable sound effects, gather pixel accommodation, and whole multimedia is possible just due to directx only. Everything visible on your desktop while playing games is just due to directx.
Directx enable integration between you gaming console and your PC hardware.
