The tread is the part of the tire that makes contact with the surface of the road. And if you take a look at different tires on the market, you'll notice a great deal of variety in their tread patterns.
Why are they so different? Because a tread pattern is a unique design that enhances a vehicle with grip and handling for specific driving conditions. Just like in a detective novel, you could identify a make of tire by the tracks it leaves on the road.
Every tire tread has four constituent parts:
Ribs are the raised section of the tread pattern, made up of tread blocks;
Grooves are deep channels which run circumferentially and laterally around the tire;
Tread blocks are the raised rubber segments that make contact with the road surface;
Sipes are small, thin slots molded into the tread blocks.
