When people talk about macro photography, they generally mean taking extreme close-up photos of an object. Typically, macro photography subjects tend to be flora or insects. This is hardly surprising though, because much finer details can be seen on these subjects through macro photography.
Photography purist define true macro photography as capturing an image where the subject is projected onto the camera’s sensor close to its actual size.
I’m not a purist when it comes to macro photography, and generally I define macro photography as extreme close-ups of the subject.