An optical drive is a CD/DVD drive made for use with your computer. As laptops have gotten slimmer and lighter and as more data storage and entertainment content has moved online, many laptop models have eschewed the traditional CD-ROM or DVD drive.
However, there are times when you still need one. You may have older computer programs you enjoy using that you want to install on a new laptop via CD. You may have a vast CD or DVD collection that gives you access to entertainment you cannot always get online. Or perhaps, you have a lot of old family documents, like photos, stored on CD and you want to access them. In any of these cases, a DVD and CD drive is essential.
Fortunately, a disc drive is often highly affordable. If you have a laptop, you will want an external optical drive that can connect via USB. If you are replacing an optical drive on a desktop computer, you will likely be shopping for an internal optical drive.