Patching means altering the software or firmware to create new possibilities. When we talk about patching receivers (like the famous Allcam patch) it means that the original receiver firmware is modified in such a way that it is able to do more than the manufacturer intended it to do.

The Allcam patch, for instance, is a modification that allows you to decode multiple coding systems on just 1 CAM. Such Allcam patches are offered for several receivers, on the web.

But also creating a new language version of the receiver operating system, requires a firmware modification and would thus be called a patch.