DirectX 11 is the latest version of the free DirectX API collection for various platforms. It is used by many games from the late 1990s on all the way to more modern years. The most common versions are DX 7 through 11, and all of them have compatibility with different games and devices. For many games, running with DX rather than other graphics engines is the best choice.
For Players And Programmers
DirectX is just a collection of graphics APIs, so many players will not notice what it does until it spits out an error. Fortunately, DX itself rarely does, though other programming fixtures linked to it can. As a developer, DX can have a somewhat high learning curve, but no worse than other graphics engines.
Let's Be Direct
In the case of some games, you'll have no choice. DirectX will simply run itself as part of the game you're playing. Other games may let you choose between DX and other graphics options such as OpenGL. In general, DX is fastest and has the best compatibility on older or more obscure devices. OpenGL for example, on the other hand, makes the most of the latest technology innovations but can be very slow on platforms that do not run it well. Overall, if you have a choice, DX is a safe and stable one.