A more thorough explanation:

Definition: Harboring an illegal alien refers to the act of providing shelter, employment, transportation, or any other form of assistance to help a noncitizen remain in the United States unlawfully, while knowing about or recklessly disregarding the noncitizen's illegal immigration status. This crime does not require the offender to be involved in the smuggling of illegal aliens into the country.

• A landlord renting an apartment to an undocumented immigrant without verifying their legal status.
• An employer hiring an individual without proper documentation to work in their business.
• A citizen providing transportation to an undocumented immigrant to help them avoid detection by law enforcement.

These examples illustrate how individuals can be charged with harboring an illegal alien by providing assistance to undocumented immigrants. In each case, the person providing assistance is aware of the individual's illegal status and is helping them remain in the country unlawfully.