These are different steps in culturing the same specimen. The culture is grown for 4-8 weeks, then inspected under a microscope to see whether NTM is present, and what type. To a trained eye, the types look different; in some cases they can be further identified by genetic testing of the bacteria.
The next step is a "colony count" - if not requested, a number is not expressed - usually recorded as few, some, many...A more exact method is to count the number of NTM colonies growing on the specimen, which is expressed by some labs as an absolute number, and others on a scales (meaningful to your doc as +1 thru +5). This helps indicate the severity of infection, and can help the doc decide whether antibiotics are needed immediately or you can "watch & wait", and sometimes whether Arikayce should be added right away.
The final step is sensitivity testing - antibiotics are applied to the colonies to see which are effective against your "bugs" so the treating doc can decide which ones to use.