The term "blue collar" is one of the types of occupations, others being “white collar” and “Pink collar”. It refers to the working class who performs manual labor requiring jobs, which may require skilled or unskilled work of physical nature. The job may be of various kind ranging from manufacturing, mining, construction, mechanical, maintenance, technical installation or any other job of similar sort. Some blue-collar occupations require highly skilled personnel, preferably who have some sort of training and certification. Other jobs may have no such requirement. Often something is physically being built or maintained.
The term “blue collar” came into use because historically people performing manual labor wore usually blue colored uniforms since it could hide a little dirt around the collar, and hence suited for manual work.
The pay scale for the labor work has a wide range and depends upon field of specialty and experience. Many workers are often paid hourly, although some professionals may be paid on the project basis or may be salaried.
In contrast to this type of job, people who perform professional jobs are said to be doing a “white collar” job. The origin of this term comes from the fact that White-collar workers typically worked in office settings and wore white, button down shirts.