There are different types of Contractors.
If you have a plumbing problem you call a plumber, electrical issue you call an electrician, if you need a new roof you call a roofer and if the AC goes out you call a HVAC company. In Illinois these trades require a special license, specific to their respective trade. What if you want to add an addition to your house or remodel your kitchen or bathroom, what type of contractor do you look for in that situation?
Usually, the term that is used is General Contractor or Builder. A general contractor has the experience to tackle a job that requires the coordination of multiple trades. In most cases this type of contractor has the personnel to handle the majority of the work using his own employees. They will still have to sub-contract out the plumbing, electrical, roofing and HVAC parts of the project unless they have state licensed tradesman on the payroll.
Most General Contractors come from the ranks of carpenters. When you think about it, it makes perfect sense. The carpentry trade covers a broad range of skills. A well trained carpenter is working on the project from the beginning of the foundation to the installation of cabinets and trim. This broad range of knowledge, and time on the project, puts the carpenter in the ideal position to ensure all the different trades work together to bring the project to completion.