Google is your friend: Be nice and visit him often. He can answer questions a lot more quickly than posting them here...
A very quick search using your subject as the search term gave 750,000,000 hits:
What is internet of things[
^]
The
Wikipedia[
^] description is about as simple as it gets.
In future, please try to do at least basic research yourself, and not waste your time or ours.
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