Render Engine: This changes the renderer (known simply as the render engine) used by the plugin. There are two choices here: DirectX and OpenGL. Which one is preferred is DirectX, with it being more stable in some emulators, and havnig a much more mature code base..
Window Mode Resolution: This sets the graphics resolution used by the plugin in windowed mode (that is, not in full-screen).
Full Screen Resolution: This sets the graphics resolution used by the plugin in full-screen mode.
Full Screen Colour Quality: This sets the bit-depth (number of colours) used by the plugin when processing in full screen mode. Often 32-bit is considered the default (and best) setting.
Full Screen Refresh Rate: This sets the speed in which the screen is redrawn (refreshed) per second. Often, higher values lead to a display with less flicker.
Display Tooltips: This option enables the use of tooltips (small information bubbles), that help prompt the user on the use of different plugin settings.
Enable SSE: This option enables the use of special programming optimizations used by the plugin, to boost speed. Specifically, this enables the use of SSE processor optimizations (if your CPU is capable of using these). Visual C++ 6 compiled builds have SSE optimizations disabled.
WinFrame Mode: This option enables the use of wireframe rendering. This option wil not render the textures or solid models. Instead it renders only the graphical "bones" of a surface or model. This option is a novelty one.
Skip frame: This option enables frame-skipping, to boost speed. However, this option can lead to a non-smooth picture, due to the skipping of certain frames being rendered by the plugin.
Hide Advanced Options: This option, if enabled, will disable some options to be usable, for the sake of simplicity. If you know what you are doing, its recommended that this is turned off.
Enable Fog: This option allows for fog effects in games that use them. Its recommended that this option is turned on.