Big data

Dear sir
Big data
Is a extremely large collection of data
Where data is collected and analyzed to reveal trends .

For example
A traffic controlling department.

Will obviously aim to minimize the traffic jam in the state .

So let’s assume junction A is affected with traffic jam and a lot of complains and accidents occur due to it .

So they may collect data for a required amount of period at the junction A .

Example implementing a sensor system to find out how many vehicles are passing through that junction A at any given time
and then
The traffic controlling department would
Use that data to analyze and reveal trends of
How many vehicles passes through that particular junction A.

at a given time .

So is this idea of mine correct regarding big data ?

Thank you .