Anaesthesia refers to a state of no sensation and can be general, regional or local. General anaesthesia involves drugs which induce a deep sleep; regional anaesthesia (epidural / spinal) involves injecting drugs around the spine to numb the legs and abdomen; local anaesthesia involves injecting drugs into the skin to numb a small area. Sedation involves drugs that produce sleepiness or a light sleep but stop short of general anaesthesia.
All of these techniques can be used alone or in combination depending on the specific procedure. The decision as to which is best for your situation will be made by your consultant anaesthetist after discussion with you.