Between Ruby and Tawny Ports the difference is in the amount of time both has spent aging in casks prior to blending and bottling.
Ruby Port is younger, has spent less time in the cask, usually only a few years. Ruby ports retain more of its natural color, and get more sweetness and fruity characteristics from the grapes then Tawny ports. As a result, its colors are more of a deep, ruby color.
Tawny Ports get aged longer in the cask, sometimes as long as 20 years, and as it matures, more of its color fades to a brownish, tawny color. In addition, its flavors are less sweet, have deeper, more complex characteristics.
Vintage Port and LBV both present a selection of very fine full bodied reds from a single year. The difference between the two styles lies in the way each is matured. Vintage Port is kept in wood for only twenty months or so before being bottled where it continues to age while being on the shelve.
Late Bottled Vintages are bottled later, remaining in wood between four and six years. During this relatively long period of wood ageing, an LBV matures and settles down. It is ready to drink when bottled, does not need to be decanted and can be served by the glass for several weeks after the cork is drawn.
Late Bottle Vintages were created to have a more high quality but very affordable port which is immediately drinkable compared to the alternative of a Vintage port.
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