The first drop-down-list allows you to select a category to limit your search to. The second drop-down-list allows you to limit your search to a particular piece of product information (e.g. Name). Once you have selected these (or left the default ALL), enter the keyword to search for.

You can further refine your search by adding a second keyword and selecting the AND or NOT operator. Selecting AND means both words must be present for the product to be displayed. Selecting NOT means the product will be displayed only if the first keyword is present and the second is not.