Traffic-Shaping refers to the modification of packet-based network protocols according to certain criteria. A frequent goal might be to forbid certain protocols e.g. for file sharing to limit data transfer rates. If intended to modify the network traffic, blocking certain ports also counts as traffic shaping.
Traffic Shaping refers to various methods to change the network load of a connection. The usual goal is to avoid clogging of a slow connection.
Example: Assume you have a DSL-connection with asymmetric up- and download speeds, i.e. slow upload and fast download. If you are sending an email while downloading a large file from a webserver, not all TCP packets necessary to continue the download will find their way to the webserver and thus the download is being delayed. A solution to avoid that is to throttle the email-upload thus that the requests for the download can find their way to the webserver.
Further reading: https://de.wikipedia.org/wiki/Traffic-Shaping
