Line maintenance: The maintenance is done on the flight line, basically on the apron out in the open. Line maintenance can be up to A check.
Base maintenance: The maintenance work is done in a hangar, with appropriate platforms perform access aircraft components.Special tools and equipments are used. Third-party just means that someone else than the operator of the aircraft is running the shop. For detailed Aircraft maintenance checks.
Component maintenance: The maintenance or repair work done on the unserviceable component to make it serviceable. This maintenance are performed in accordance with Aircraft Maintenance Manual or Component Maintenance manual.These components can be LRU (line-replaceable unit). Components could also be as large as a whole engine which needs to be serviced in a special shop and is removed during base maintenance.