Rioja is a famous red wine that comes from the Rioja region in Spain. It's made from Tempranillo grapes, and can be aged for several years in oak barrels. Rioja wines can be classified into four categories based on the aging process:

1. Rioja joven - A young, fruity wine that is aged for less than a year.

2. Rioja crianza - A wine that is aged for at least two years, with at least one year in oak barrels.

3. Rioja reserva - A wine that is aged for at least three years, with at least one year in oak barrels.

4. Rioja gran reserva - A wine that is aged for at least five years, with at least two years in oak barrels.

Rioja wines have a medium to full body, with flavors of red fruit, vanilla, and spices. They are known for their ability to pair well with a variety of foods, from grilled meats to stews and cheeses.