BEE is on the road to Web Services. The main promise of the Web Services technology is distributive processing among software components on geographically separated machines of heterogeneous platforms.
The concept of a "connector" in the current implementation of BEE is experimental aiming at a Web Services model in the coming version. A BEE Connector enables the client to send a request to the server without having to refresh the whole page.
For example, when you want to obtain new information (e.g. the next data record) or do a little processing on the server (e.g. check the price of a product), you will need to press a button to submit a form. The server will send you back a whole new page even only a small part of it contains new information or processing result.
This all-or-nothing approach not only wastes time and bandwidth on the client side, but also increases server loading and causes other side-effect in page refreshing (such as incorrect page hit statistics and extra processing other parts of the page might have.)