What is this for please

I'm very new to Arduino and I got this http://www.freeimagehosting.net/mdo6v in my starter kit.

Can someone please tell me what it is and what I would use it for?

Thanks

It is a "Prototyping Shield" Support circuits (LEDs, temp sensors, etc.) are placed on it, makes for easier interfacing.

It is a type of proto shield. Here is a description of one (similar to the one you have): http://arduino.cc/en/Main/ArduinoProtoShield

Thanks very much for your answers.

The link was very helpful.