阻挡 (zǔ dǎng) means 'to block, obstruct, or hinder' and focuses on physically or figuratively stopping progress or movement. It is similar to 阻碍 (zǔ ài) but more concrete and active (e.g., blocking a path or view), while 阻碍 is broader, covering abstract hindrances. Compared to 挡 (dǎng), which is often for shielding or covering (like blocking light), 阻挡 implies a stronger, more deliberate obstruction.