Socks can isolate the feet from the boots to prevent abrasions, and also play a protective role of the pad. Socks made of woolen socks or synthetic fibers can protect your feet, but cotton socks will loosen after absorbing water, easily rubbing the skin on your feet, and have no protective function.
The sweat absorption of socks is very important, because most hiking shoes do not have the function of breathing, and the sweat on the feet will gradually gather until the shoes are taken off. Socks made of synthetic fibers (including polyester, nylon, and acrylic) are easier to dry than wool socks.
Most climbers wear two pairs of socks, and the inner layer wears thin inner socks, which can drain sweat to the outer layer and keep the feet dry. The outer socks are generally thicker and rougher, which can absorb the moisture of the inner socks, and can also be used as a cushion to prevent injuries to the feet due to friction.
Of course, there are many exceptions. Some climbers want to enhance the fit of climbing shoes, so they don't wear socks or only one layer; hikers wear only one layer of socks when wearing hiking shoes in the summer to keep their feet cool. Special attention should be paid to whether there is enough room for the feet when wearing multiple pairs of socks. If socks hinder blood circulation, wearing more socks will not keep you warm.
Before wearing socks, wrap protective twill cloth or sports tape on the heels and other places where blisters are likely to blister. This is very useful when wearing new boots or when the skin of the mountain has not become delicate for a long time. In addition, spraying powder in the boots and socks to keep the feet dry is also a way to prevent blistering.
In expeditionary or extremely cold weather, a layer of socks can be added between the two pairs of socks to block moisture. This kind of socks are waterproof but not breathable, which seems to violate the previous dressing principles. Socks that block water vapor are best suited to wear in extremely cold weather, which can reduce frostbite, but if the moisture stays in the boots for a long time, it will cause serious trench foot disease. If you wear socks that block moisture, keep your feet dry at least once a day.