CSSstatic (mặc định, theo flow). relative (offset từ vị trí gốc, vẫn chiếm space). absolute (thoát flow, relative với positioned ancestor). fixed (relative với viewport). sticky (hybrid relative+fixed).
static (default, follows document flow). relative (offset from its normal position, still takes up space). absolute (removed from flow, positioned relative to the nearest positioned ancestor). fixed (relative to the viewport). sticky (hybrid of relative and fixed).