Why use one
Engraving too close to an edge risks the design running off the item, and looks cramped even when it does not. A gutter reserves a consistent border on every plate in the run. It also gives auto-layout a boundary, so text sized to fit stays inside the intended area rather than reaching the physical edge.
Setting a gutter
The gutter is enabled in the plate settings, with a size and an option to show or hide it on the canvas. A visible gutter is a guide only and is never engraved.
Setting it as a default
Templates carry their own default gutter spacing, so a shop standard is applied automatically to every design started from that template. See Templates.
Gutters compared with bed margins
A gutter is inside a single plate. Bed margins are around the whole sheet of material. Both may be needed, and they are set in different places.