Handicap is a type of bet that evens up the chances of both players or teams winning a specific event. This is done by giving one side an advantage. This could be in the way of an extra goal or more points. It is also sometimes referred to as 'the spread'.
A disability is an inability or restricted ability to perform an activity within the normal human range, e.g. being unable to walk. A handicap is a disadvantage resulting from impairment or disability that limits the social role of an individual, e.g. being unable to work somewhere due to limited access.