A lens that provides continuous focusing from infinity to extreme close-ups, often to a reproduction ratio of 1:2 (half life-size) or 1:1 (life-size). Nikon's version for their "macro" is "micro", eg. 105mm F2.8 Micro-Nikkor.
A lens that provides continuous focusing from infinity to extreme life-size 1:1 close-ups. Also used as a copy lens because of its highly corrected design and close-focusing. Macro lenses can also be used at ordinary subject distances (see: Copy, Close-up lens& Extension tubes)
lens with the ability to focus from infinity to extremely closely, allowing it to capture images of tiny objects in frame-filling, larger-than-life sizes. Sometimes called a "Close-up lens," although a close-up lens is usually a lens attachment for close-ups and does not generally have the ability to focus on infinity.
A lens designed for close-up photography, i.e. within about 20cm. Macro lenses are the preferred choice for photos of flowers and insects. Popular focal lengths are 50-60mm, while 90-100mm macro lenses are useful when you need slightly more distance to your subject.