Harbours provide sheltered areas for loading, unloading, and repair of vessels. They are classified as natural, semi-natural, or artificial. Natural harbours use existing landforms, while artificial harbours require complete human construction. Good harbours have sufficient depth, secure anchorage, and wide entrances. They feature berths, breakwaters, piers, wharves, and jetties to facilitate cargo operations. Planning considers traffic volume, shelter, construction materials, and environmental factors. Harbours serve commercial, fishing, military, and refuge purposes depending on their layout and facilities.