In electronics, the term "copper pour" refers to an area on a printed circuit board filled with copper (the metal used to make connections in printed circuit boards). Copper pour is commonly used to create a ground plane. Another reason for using copper pour is to reduce the amount of etching fluid used during the manufacture.
A distinctive feature of copper pour is the backoff (or stand-off) - a certain distance between the copper pour and any tracks or pads not belonging to the same electrical net. A copper pour therefore looks like it flows around other components, with the exceptions of those pads which are connected to the copper pour using thermal connections.