A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen,[1] the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.
For example, a 700 x 20 C road tire would be a 20-622; a 700 x 38 hybrid tire would be a 38-622. The width difference between these sizes would make them less-than ideal replacements for one another, but any rim that could fit one of them would work after a fashion with the other.
Finally, the 16 indicates the tire's diameter so this particular example means it fits a 16 wheel. For more information on reading these measurements, you can check here. Also, some tire manufacturers list their tires in inch measurements instead of metric, so here is a handy conversion chart.