Viewport 2.0 is the viewport and hardware renderer in Maya - it's the way you view your scene.
Optimizing Viewport 2.0
For tips on how to optimize performance for Viewport 2.0, see Optimize Viewport 2.0.
Troubleshoot Viewport 2.0
For solutions to common Viewport 2.0 issues, see Troubleshoot Viewport 2.0.
OpenGL, DirectX 11, and OpenGL Core Profile
You have a choice of four rendering engines in Viewport 2.0: OpenGL - Legacy, DirectX 11, OpenGL- Core Profile (Compatibility) and OpenGL - Core Profile (Strict).
Select Window > Settings/Preferences > Preferences to open the Preferences window. Then select the Display category and then your Rendering engine under the Viewport 2.0 section.
Selecting DirectX 11 as your rendering engine lets you render DX11 hardware shaders in real-time in the viewport. See Run Viewport 2.0 in DirectX 11 mode for more information.
Selecting OpenGL- Core Profile (Compatibility) or OpenGL - Core Profile (Strict) as your rendering engine lets you create custom GLSL (OpenGL Shading Language) shaders which support lighting, textures, shadows, and tessellation. See Run Viewport 2.0 in Core Profile mode.
See also Rendering engine (in the Viewport 2.0 Options) for more information.