A "normal" is the direction a face is pointing.
If your material looks black or invisible, you have inverted normals. Fix it by selecting all (A) in Edit Mode and pressing Shift + N (Recalculate Outside). blender masterclass learn 3d modeling from az top
When you build a robot arm, you want the hand to move when the forearm moves. This is parenting (Ctrl + P). The child object inherits the motion of the parent. A masterclass will teach you to set origins before parenting, so rotations work cleanly. A "normal" is the direction a face is pointing
A-to-Z Tip: Sculpting is intuitive but chaotic. Always do a final Retopology pass after sculpting to create game-ready low-poly geometry. If your material looks black or invisible, you