An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain.
Analgesics are medicines that are used to relieve pain. They are also known as painkillers or pain relievers. Technically, the term analgesic refers to a medication that provides relief from pain without putting you to sleep or making you lose consciousness.
Two of the most common groups of pain killers are nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids (narcotics).