A barouche was a medium-sized carriage popular in Georgian and Victorian England; it was a four-wheeled carriage pulled by two horses, and it was not enclosed, although it did have a hood that could be raised and lowered. Although the barouche was a four-seater, the hood would generally only protect the two rearmost seats. This was generally not a problem, as one owned a barouche to go promenading, and there was no point in doing this in bad weather.
The barouche-landau was essentially the same vehicle, with the addition of a second fold-up hood for the front seats; these front seats faced the rear, and the rear and forward hoods could, in many models, meet in the middle to enclose the carriage. This gave it the appearance of being a small landau; landaus were larger, fully enclosed (but still convertible) carriages pulled by four horses.
As with the barouche and the landau, the barouche-landau was an about-the-town carriage, and was not suited to long journeys. While these carriages were usually somewhat small (generally carrying four passengers, but occasionally six), it is worth noting that the driver's seat could hold the driver and perhaps one passenger, and it was not beneath a young gentleman to take the reins. Indeed, the young bucks of the infamous Four-in-hand Club and Whip Club preferred to drive barouche-landaus with sets of four matched horses, the Regency equivalent of a over-powered sports car.