I shall leave it to the experts on this forum for the finer details but tissue culture is taking a living cell or group of cells and placing them in a plant growing culture similar to growing bacteria. Eventually, if all goes well, a tiny plant will form that is supposed to be a clone of the original. The downside as I have read is the plants are weak as compared to field grown plants. Also, I have read they may or not produce the color and quality of a field grown plant. The upside is the process is cheap and thousands can be reproduced at a very low cost and more quickly than field grown. No huge investment in land is required.
