Micro-photography is photos taken through a microscope, of things so small we can't really see them with the naked eye. Whereas macro photography is super-closeup photos, lying between what a camera can normally do, and micro-photography, generally of subjects smaller than the sensor (though this is based on 35mm photography, so equivalent to a "full frame" sensor, 24mm x 36mm.)
Most "macro lenses" only go to 1:1 with the built-in focussing, but you can get rings or bellows to put between the camera and lens. The mere extra space focuses the lens much closer. Technically you can use a normal lens also with these things, but it's not optimized for macro distances, so the pictures won't be very sharp.
Green beetle – 30 frames combined (Credit: Iddo Genuth)
The reason for the many combined frames (done in the computer with special software) is that one of the big challenges of macro photography is the super-duper-narrow depth of field.