Parts of a concentric (most popular) castle are:

• Inner curtain (inside wall)
• tower (corner tower)
• inner gate
• outer gate
• outer curtain (outerwall)
• drum tower (inside wall towers)
• moat (river around the castle)
• gatehouse (where gates were lifted)
• keep (millitary residence)
• great hall (dining room)
• drawbridge
• donjon (dungeon/jail - where people were left and forgotten about)
• garderobe\loo\privy
• pantry
• kitchen
• solar (bedroom)
• barbican (portcullis)
• bailey (courtyard)