A dozer is a multi-purpose, heavy duty, earth moving machine that is used to dig up soil, rocky surfaces, and roads, etc. To put it simply, a dozer is just another term for a bulldozer. A dozer is fitted with either wheels or tracks to move it along over the terrain much like a tank. If the ground is muddy or wet and boggy the dozer will be fitted with extra-wide tracks called swamp tracks so the machine won't sink into terrain. A dozer can come with multiple attachments such as blades, ripper claws, and scrapers, etc. Dozers are specified according to their engine horsepower, blade width and size, number of cylinders and capacity, number of speeds available, the max torque that can be generated, overall weight, and number of attachments that can be fitted, etc.
The very first versions of dozers were basically modified tractors that had a large metal plate mounted to the front of the vehicle. Dozers were used to clear obstacles and shift earth, stone and assorted rubble. The metal plate at the front evolved into a curved shovel blade which could be operated by the driver. The shovel can be also used to pick up and move material.
The blades on early dozers were operated by pulleys and cables. These days, most dozers use hydraulic systems. Most modern dozers also have a ripper claw with a hardened tungsten steel tip mounted on the back end of the vehicle opposite the shovel. The ripper is basically used to break up compacted ground or paved areas.
The function of a dozer is usually determined by what type of dozer blade has been installed on it. Some dozers have scoop shovels which are mounted to huge hydraulic arms. These dozers are designed to lift snow from roadsides and load it into dump trucks, and load ore into hoppers at mines. Dozers are also used in mining applications to dig up the surface and remove debris. In construction applications, farming and road building, it finds similar use. Defense and anti-terror squads often use them to clear minefields of dangerous explosives and such vehicles have special armor plating along with bulletproof windows for the operator.