You may initially think that the eyelet here is the one that refers to a piece of clothing, but this time, this refers to the item that you will use when you want to make cutouts or holes in a piece of fabric. The eyelet may be made out of different metals, but most of the time, this is made out of brass.
The grommet can sometimes be mistaken as an eyelet because they somehow look similar, but the grommet can be used more for some heavy-duty fabrics. There are some fabrics and other types of items that would need to be cut.
The grommet is usually ring-shaped. The grommet can be used for carbon fiber, for wood, or even for honeycomb. It can obviously be used for different items that people may need.