People may wear uniforms for several reasons. The uniform will help the people to feel a team spirit so that they work well together. They may also help members of the public to know who they are, e.g. in a department store a customer can tell who is a member of staff, or in the street people will recognize a police officer. Uniforms may also be worn because they are practical, e.g. it might keep them safe when operating machinery or keep them clean when doing their work.