Uniform refers to a group of people from the same group wearing a uniform style of clothing to identify the common things they are doing, or to separate their occupation or special status, such as: students, police and military. Uniforms can also be classed. For example, in Hong Kong, the uniform of the primary nurse is pink, and the uniform of the official nurse is white. Some professional uniforms are uniform in the world, such as the uniforms of civil aviation pilots, generally black, wearing flying signs and shoulder cards, and stitching with representative marks on the cuffs, wearing big hats and navy uniforms, etc. . Schools in some places, such as some countries in Asia, require students to wear school uniforms to go to school.