Unemployment benefits are sums of money given to the unemployed by the government or a compulsory para-governmental insurance system. Depending on the jurisdiction and the status of the person, those sums may be meager, covering only basic needs (thus a form of basic welfare), or may compensate the lost pay somehwat proportionally to the previous earned salary. They often are part of a larger social security scheme.
Additional meaning of Unemployment benefit:
Unemployment benefits are generally given only to those registering as unemployed, and often only conditions ensuring that they seek work and do not have a job.