How does FAH work?

General
The software involved in the Folding@home project consists of many collaborating parts: several kinds of servers and a variety of clients. Folding@home uses a client-server model where the clients receive a work unit (WU) from the servers, process it and return the processed results back to the servers where the results are analyzed.

The general sequence of events is:
 * 1) a client sends an assignment request to one of the Assignment Servers
 * 2) the Assignment Server assigns the client to a Work Server
 * 3) the client downloads the assigned WU from the Work Server and starts processing it

When the client is done processing the WU, the sequence of event is:
 * 1) the client attempts to upload the WU to the Work Server from which it downloaded the WU,
 * 2) * if the Work Server is unable to accept the WU, the client attempts to send the WU to the Collection Server
 * 3) ** if the Collection Server is also unable to accept the WU, the client will keep the WU in its queue and will attempt to upload it at periodic intervals
 * 4) the WU is credited and the points are added to the user configured on the client who sent it

After a WU is uploaded by a client and depending on the results, further WUs are generated based on the uploaded WU and made available for assignment to a client.