The material a wader is manufactured from varies depending on the water temperature that wader was intended for. Waders intended for warm-to-moderate water temperature are often construction from fully waterproof material or a waterproof/breathable membrane like Gore-Tex, whereas cold-weather waders may use insulation or material like neoprene.
Like the gaiters that keep snow out of your snow boots, gravel guards secure around the top of your boots to prevent sand, gravel, and other debris from getting in your wading boots. These guards can be a huge help in rivers and creeks that are particularly silty, rocky, or thick with debris. Gravel guards are a common feature on most waders.
Wading booties are footwear integrated into the wader designed to keep your feet warm when you're wading in cold water. Often, these booties have integrated drain holes, reinforced taping, and some form of hook-and-loop closure at the instep. You may see wading socks also referred to as 'booties.'