Eyelet curtain has metal-edged holes at the top which are usually silver in colour. The curtain can be made of heavyweight fabric, lightweight fabric, or lining with thin material.
 
Before hanging an eyelet curtain, a curtain rod may be inserted into the holes. Or, as an alternative, curtain rings can be put through each hole and then placed around the curtain rod. Either way, it looks attractive, depending on what works best for your room in terms of style.