While a visa and Green Card are both legal documents issued by the government of the USA, their eligibility requirements, privileges, and rights differ.
The primary distinction between the two documents is that a visa is a temporary permit and a Green Card is a permanent authorization to stay in the USA.
A visa would only allow you to visit and remain in a country for a given period of time for a specific purpose. The temporary status of a visa doesn’t allow the holder to engage in work unless it specifies a particular type of employment. Visas also have a date of expiry on which the authorized time of stay is terminated, thus compelling the visa holder to leave the country.