A. Contractors are usually brought to a client site to do a project that requires skills the client employee team doesn't possess or to help out on a temporary project for which the company doesn't have enough people to handle. An example might be a Windows NT 4.0 to Windows 2000 migration. Contractors might be deployed as a team from a contract company or as individuals.
Contractors generally are hired for a short term of a few months to a year. Contractors receive no benefits such as insurance, retirement plans, etc., unless provided by the contract company. Contractors might make two or more times what their staff counterparts make. This attractive pay rate is offset by the possibility that you might spend time between projects with no income at all. Contractor positions are very vulnerable to budget cuts. Often, management will lower the axe on the contractors because they can let them go with little notice and no severance pay obligations.