Anchor
An anchor is a device, normally made of metal, used to connect a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin "ancora", which itself comes from the Greek ἄγκυρα ("ankura").
Wall plug
Nowadays, one of the most common designs for light loads is the split-ribbed plastic anchor. It consist of two halves that increase their separation (split) as the screw penetrates between them. As its name suggests, this type of anchor also has ribs on the outside to prevent the anchor from slipping out of the hole as the screw is driven in. This type of anchor is also known as a "conical screw anchor".