What is the difference between statement and expression?

expression includes only identifier, literal, and operator and is later expressed as a "value".

Here, the operator includes arithmetic (+, -, /, etc.), boolean (and, or not), () (function call), [] (subscription), etc.

3 + 5
map(lambda x: x*x, range(10))
yield 7

You can think of a statement as a more comprehensive "line."

Because expression alone can make a line, expression is also included in the statement, so it is also called an expiration statement.

print 42
if x: do_y()
return
a = 7