If you live in a part of the country that sees frequent sub-freezing temperatures and snowfall during the winter, you'll have to choose between all-season tires that remain on the car all year round and winter tires that are put on as winter approaches and removed in the spring. The choice depends on the severity of winter in your region, the degree of road maintenance performed by your local community and your personal preference. Either way, it should be an informed decision.
All-season tires are the standard for most mid-priced vehicles. They offer moderate to good traction on dry roads, in the rain, and even in the snow. They provide longer wear because the rubber compound is harder and more durable than that used for winter tires, but the trade-off there is that when temperatures drop the cold makes the rubber even harder still so it loses some of its ability to grip the road.
Winter tires have a tread designed to provide a better grip on ice and snow covered roads. This doesn't mean that your control or stopping ability will be as good as it is on dry roads, but it will be better than all-season tires when driving in wintry conditions. Winter tires may make the difference between getting up that hill when there's a shallow covering of snow on the road or having to wait for the plow to come by. The extra edges in the tread of winter tires may cause a noticeable increase in road noise when compared to all season or performance tires.
As mentioned before, the rubber compound used in winter tires tends to be a bit softer and is designed to retain that softness even in very cold conditions. Because winter tires tend to wear out faster than all-season tires, they should be taken off at the end of the winter and put into storage for the following year as long as the tread depth remains within manufacturer's recommended guidelines.
Whichever tires you choose, proper tire pressure is a must for top performance.