Difference between analgesia and anaesthesia

Key Difference – Analgesia vs Anesthesia
  The key difference between analgesia and anesthesia is that the anesthesia is an induced, temporary state with one or more of the following characteristics: analgesia (relief from or prevention of pain), paralysis (extreme muscle relaxation), amnesia (loss of memory), and unconsciousness. Analgesia can be achieved by giving a pain killer or an analgesic to the patient. Basically, analgesia is a part of anesthesia. Anesthesia is given in carefully selected situations and, in contrast, analgesia is given whenever a patient needs pain relief.