The H-1B visa is a temporary worker's visa for specialty occupations. The H visa is job and site specific; once approved, the employee is eligible to work at the job for which that visa was approved and ONLY that job.

The regulations define a "specialty occupation" as requiring theoretical and practical application of a body of highly specialized knowledge in a field of human endeavor including but not limited to architecture, engineering, mathematics, sciences, biotechnology, medicine and health, education, law, accounting and theology, and requires the attainment of a bachelor's degree or equivalent.  Additional information regarding the requirements for an H-1B  visa, can be found here.