Red wines come in many varietals and blends. The different varietals range from Super Heavyweight to Featherweight (as referred to on Delong's Wine Grape Varietal Table.) Cabernet Sauvignon, Merlot, Shiraz, Pinotage and Carmenre' are among those at the fuller bodied end. Pinot Noir, Tempranillo and Sangiovese are on the light to medium weight end.
Each varietal of grape has it's own unique characteristics-including body, flavor, aroma and color. A Cabernet may be described as rich fruit forward with blackcurrent and cherry flavors...full bodied and heavily oaked. A Pinot Noir, on the other hand, may be described as rich, silky and smooth with notes of toast and raspberry...light or medium bodied with a medium oak intensity. Tasting these two wines next to each other...you can certainly tell them apart
There are many wines made from a blend of 2, 3 or more grapes. These blends sometimes bring out "The Best of Both Worlds!" You may not care for a Shiraz by itself, but blend that Shiraz with a Cabernet and you have a harmonious mixture of flavors from both grapes. There are times that one grape or the other will be dominant, but I notice through the aging process they will transform and different charateristics will emerge from the wine.
Aging red wine can certainly be beneficial. The "bigger" a wine is the more it will benefit. By aging, the wines will evolve with more complexity and flavor. The strong fruit flavor of a young wine will mellow into a drier finish. The harshness will soften to a smoothness.
Thank you for listening to my ramblings! I love all types and styles of wine, each one being unique in it's own way. I like to suggest that you venture out of your comfort zone and try some wines that you normally wouldn't drink. So many wines...So little time!