Flow, or Flow state?

flow

/flō/

verb

1.

(of a fluid, gas, or electricity) move along or out steadily and continuously in a current or stream.

"from here the river flows north"

2.

go from one place to another in a steady stream, typically in large numbers.

"the firm is hoping the orders will keep flowing in"

noun

1.

the action or fact of moving along in a steady, continuous stream.

"the flow of water into the pond"

2.

a steady, continuous stream of something.

"she eased the car into the flow of traffic"

What is a flow state?