Hood is an article that covers most of the head and neck, and sometimes the face. Hoods usually cover the top of the head for protection from the environment.
A balaclava, also known as a balaclava helmet or Bally in UK slang or ski in US slang, is a kind of headgear designed to protect the head and part of the face. Depending on the style and how it is worn, it can be rolled into a hat to cover the crown of the head or folded down as a collar to protect the neck. Balaclava came from their use at the Battle of Balaclava during the Crimean War of 1854. British troops knitted this kind of headgear to help them during the bitterly cold weather.
A Neck gaiter also called a neck warmer or a buff is a form of clothing worn around the neck for warmth. It’s a closed tube of fabric often made of thick fleece, merino wool, or knitting material. Neck gaiters can be pulled up over the mouth to insulate from wind or sand.