The 185 is the measured width of the tire when it is on the wheel. The 75 is the tire series, which represents the height of the tire. The R represents the construction of the tire, R means that the tire was made using radial plies; you may also find B or D meaning that the tire was made using the bias ply methods. The 14 is the wheel rim diameter on which the tire should be fitted.
You will also find the name of the manufacturers and the words “tread wear” which will be followed by a number. This is to indicate how long the tread will last, the higher the number the better the tread. Traction and temperature is another thing you may find on your tires, these would be followed by a letter. Traction you may find followed by an AA, A, B, or C. This represents the ability of the tire to stop on a wet surface, with AA being the best and C the worst. Temperature will be followed by an A, B or C, this indicates the tires ability to control heat, with again A being the best.
The other thing to consider before buying your tires is the type of surfaces and weather conditions they will be subjected to. If you travel in places that suffer long snowy periods you could consider specially designed tires for snow and mud covered surfaces. These tires have MS, M&S, M/S or M+S marked on them and has passed safety guidelines; the tread on these tires has large enough grooves to give you the traction needed to drive in these conditions.
There are also specialized tires for driving on wet roads; these tires have a deep groove running down the centre, all around the tire. This enables the water to escape under the tire which prevents hydroplaning; this occurs when the tire loses contact with the ground and begins to plane on the water.
However all season tires provide a tread that is suitable for wet and dry conditions which include snow, these tires are adequate for all round conditions.