The difference is quite simple. A roofing contractor as stated to the left is a basic label role describing a roofing company owner. A CEO of a limited roofing company would use the name during consulting with high profile clients to regular clients of their own roofing business etc. Their field duties include, roofing contracts, the legalities of guarantees, and problem solving issues. They spend time with advertising consultants, and handle their companies roofers, managers, and equipment inventory of their operating company. They have experience with many types of manufactured products, and can run crews of roofers in various areas of the roofing industry.
Today they can even own or run multiple roofing companies that focus on different areas of the roofing industry. They work each and everyday in the roofing industry, even in the snow. After 20 years of service they can take a role of inspector or roofing consultant.