Exclusive Economic Zone (EEZ) is an area in the ocean where only one country gets to look into and do economic activity, such as mining underwater resources and fishing. In the case of islands far from the mainland, EEZ starts at the coasts of the islands. Normally, EEZ goes out to 200 nautical miles (370 km), unless EEZs of two or more countries overlap. Many EEZs actually overlap; countries argue over where their outermost boundaries of EEZ should be.
It is different from territorial waters in that ships and submarines from other countries can freely travel without any permission. However, this is under the condition that they are just passing by and not taking any resources home.
Images for kids
Baselines and EEZ claims in East and Southeast Asia showing the amount of overlap in the disputed South China Sea (the Spratly Islands in particular). People's Republic of China: The baseline and EEZ limit of the Spratlys have not been officially published, hence they are calculated based upon features that remain above sea-level at high-tide according to what is set forth in the ratified UNCLOS III. Mischief reef and Subi Reef are naturally above water only at low tide.
Canada's exclusive economic zone and territorial waters
Exclusive economic zone of Mexico
Portugal's Exclusive Economic Zones plus submitted Extended Continental Shelf to the UN
Exclusive Economic Zone Facts for Kids. Kiddle Encyclopedia.