I need help figuring out what technologies Amazon uses when you search a product and then on the left side of the page it has the option to check boxes limit your search.

Example, you search for digital camera and then you can further narrow your search by selecting either point and shoot, or slr and also narrow the search further by megapixels or price ranges, etc.

I have an idea for a web application that could utilize something similar to this, but I don't know what it is or how to do it.

Help?

Thanks