CBSE Class 8 Answered

Ports are towns or cities with a harbour or access to navigable water where ships load or unload. Maritime transport is essential to the world's economy as over 90% of the world's trade is carried by sea. In wake of these figures, some port cities become industrial, financial and service centres and political capitals because of their water connections and the urban concentration which arises there and later draws to it railways, highways and air routes. Water transport means cheap access. Many of the world's biggest cities, for example, London, New York, Shanghai, Istanbul, Buenos Aires, Tokyo, Jakarta, Calcutta, Philadelphia and San Francisco began as ports - that is, with land-sea exchange as their major function and later due to the availability of cheap transportation facilities also became industrial centres.