
There are some obvious differences between summer and winter tires, for example, winter tires have many more “sipes” in the tread. These sipes are all little grooves that open and close while driving with the purpose of “grabbing” snow off the road. So if you clearly see a lot of sipes on your tire, then you definitely have winter tires.
The left photo is a winter tire (lots of sipes).
The right photo is a summer tire (few sipes).

Another easy way to recognize a winter tire is to look for 1 of the following 2 logos.
In the left photo, you can see the logo 3PMSF (3 Peak Mountain Snow Flake).
In the right photo, you can see the logo M + S (Mud + Snow).

What exactly do these logos want to say?
Today, the 3PMSF is the new symbol for winter tires. When buying new winter tires, there is a fairly good chance that you will find this symbol since manufacturers want their tires to be homologated in all European countries in winter.