First, let's clear up the nomenclature. Curtains are known by many names, some are actually a distinction and some refer to the same thing. These names include: curtains, drapes, drapery, draperies, drapery panels and curtain panels. I think there's even some confusion amongst the so-called experts and if you asked the average person what the difference is between curtains and drapes, I bet you they wouldn't know. Aren't they all the same? Apparently not.
Curtains and curtain panels are the same thing. According to Better Homes and Gardens, ” curtains are generally lightweight, unlined and suspended from a rod by simple tabs, rings or rod-pocket casing.” A rod-pocket casing is simply a sewn flap at the top of the curtain where you push the rod through to hang. Curtains are decorative and casual and easy to make yourself, if you were so inclined. Imagine, a country home with sheer curtains pulled back, a typical way to utilize them. They don't do much for light control but add warmth and color to a room. Lastly, curtains panels can be floor-length or just long enough to cover the window casing. If you add a lining to curtain panels, you start approaching the look of drapery panels.
Draperies, drapes and drapery panels are the same things and are typically lined and floor length and again, according to Better Homes and Gardens, “…often attach by hooks to a traverse rod. A cord mechanism that hangs behind either the left or right panel draws both of the panels open and closed.” Here we've moved into a more formal, mechanized window covering, as opposed to curtains which you would open and close by hand. Drapes are typically pleated, though not always and offer a much fuller, richer look. This also affects how much room they take up when fully opened. The term for this is, “stackback.” The way to understand stackback is to imagine the amount of space, or width that all this fabric takes up at opposite ends of your window when fully opened. So, if your window or sliding glass doors (which require more fabric) have minimal wall space around it, you may want to consider curtain panels which take up less room.
As for fabrics, both for curtains and drapes, the choices are many and varied. You can dress-up your window for a more formal look with fabrics like silk dupioni, velvet, faux dupioni or, you can dress-down with linen and cotton. Most of these fabrics can also come with textures if you desire that look.
In the realm of color choices, the sky's the limit. There are solid colors, prints, plaids, stripes, sheer fabrics and more. So, when it comes to interior decorating, drapes and curtains are one of the most versatile window treatment choices available.
When it comes to drapes there are still a few more options available that will affect the appearance. These are French pleats, also known as pinch pleats which is the traditional look for drapes with a three-finger grouping of fabric that is pinched a few inches below the top of the drape. Then there is the inverted pleat option where the pleats come together at the top of the drape instead of flare-out like the French pleat. Grommet style drapes come with built in rings, or grommets which are sewn into the fabric at the top of the drape. With these you can just weave the rod through to hang. Lastly, there's the rod pocket style. These drapes have a pocket sewn into the top of the drape that receives the traverse rod.