There are three types of Port Wine: White, Tawny and Ruby. White Port is made from white grapes, whereas Tawny and Ruby are made from red grapes.

White ports

White Port offers a range of colours that can vary from pale white to amber.
There are different levels of sweetness, and types: seco (dry) is quite sweet, meio seco (medium dry) very sweet, and doce, which is, in fact,  extremely sweet. There are some new styles of port: sweet, fortified and rosé, this is especially made to drink chilled, on its own, or in cocktails. Food and Wine Pairing 
White Ports are consumed as an aperitif, sometimes by itself, with ice, mixed with tonic, or in cocktails. There are more expensive versions, with more intense flavours, which are best served chilled and served as an aperitif. Ruby ports
Ruby ports have a red colour tone that goes from light to dark red, almost black.
Ruby Ports are very sweet and more fruitier than tawny ports.
In the past vintage ports have to be kept for years to soften and become drinkable. Nowadays, there are modern methods in the vineyard plus the spirit used to fortify wines has much more quality. As a result, vintage ports are more balanced, with less tannins, so they can be consumed after a few years. Some categories of Ruby ports are: Crusted, Late-Bottled Vintage (LBV), Late Bottled, Reserve, Premium Ruby and Ruby.

Food and Wine Pairing 

Ruby is best consumed at cool room temperature. It makes great companion to some cheeses, such as Queijo Serra da Estrela, Queijo de Azeitão, Cheddar, or unpasteurized Brie in the case of LBV. They are also a good with dark chocolate or coffee desserts.

Tawny ports

Tawnies are amber-coloured to brown, and taste like dried nuts, and fig fruit. This is the result of years of slow oxidation in large wooden vats.
Tawnies can be Colheitas (specifying a vintage) or Aged Tawny (the decades are showed  on the label, and can range from 10 to 40 years). The alcohol level is higher the more decates appear on the label.

Food and Wine Pairing

Colheitas and Aged Tawnies are best served chilled, in summer or winter. They can be consumed as an aperitif, or drunk at the end of the meal, perhaps with some snack to nibble. These wines match perfectly one of the best cheeses in Portugal ― Queijo Serra da Estrela.