Janitors are professionals who manage the cleaning process in private businesses and public buildings. A janitor may find work with a private company, as part of the support team of an office building, or as an employee of a public service system. While work as a janitor does not generally require any level of higher education, it is not unusual to find persons who occupy supervisory roles within the janitorial profession to have at least some college experience.

The general responsibilities of most janitor positions involve routine cleaning tasks. These will often include removing trash from waste cans in offices, vacuuming carpets, sweeping floors, and in general keeping the space in an orderly fashion. In many cases, a janitor may also handle climate control functions with the building as well. This may include keeping a furnace in proper working order, handling the function of thermostats, or keeping a boiler system in proper repair. A janitor often also troubleshoots with plumbing issues, handling maintenance tasks with hot and cold running water, replacing leaky pipes and faucets, and also replacing sinks and toilets when necessary.

A janitor who works within a school or a government owned public building is often referred to as a custodian. Along with basic cleaning responsibilities, custodians may handle other responsibilities, such as seeing that doors are locked after hours and that any electronic alarm systems are properly set before the building is closed for the evening. The head custodian may also oversee a cleaning crew, depending on the size of the facility.

While a janitor may work during the daylight hours, it is not unusual for many cleaning professionals to work during the evening. This is especially true with office buildings, where the janitor will be able to work without disturbing people who would prefer to work without a vacuum cleaner running or someone mopping or emptying trash receptacles.

A janitor may work for a specific company, or be the employee of a cleaning service that is contracted to handle cleaning and maintenance functions. Many janitors enjoy employment benefits with a full range of benefits, while others may work with minimal benefits and a relatively small amount of pay.